Drag the parent animationset onto the child animationset, select the lockes bones, and apply the "Zero" preset. In your case, this is what you have to do:

- Drag the "inkling_boy_blue..." animationset on the left on top of the "armor_jacket1" animationset in the animationset editor on the left
- Expand the "armor_jacket1" animationset and select all the bones with lock icons beside them, but no bones without the lock icon
- Click and drag the "Zero" preset in the upper right of the animationset editor all the way to the right

All right! Now it's working perfectly!, Thank you so much for the help! :)

Hm... sorry to disturb you but the problem is back again :( , now I'm trying with a new object, this time a hat, but the same method doesn't seems to work... I attach the Inkling animation set to the hat cap015 (I Drag the parent animationset onto the child animationset as you said), then I select all the marked bones with a padlock...
Here is a pic with all these steps performed:
https://s30.postimg.org/66zy1ln1b/Sin_t_tulo.png

I think it is well done until there since the other jacket attached to the inkling model perfectly!

Now... when I try to drag the Zero bar to the right here are the results:

https://s30.postimg.org/fqxc8fiin/Sin_t_tulo.png

If you compare these 2 pics, you will see the only difference is the hat goes down, but it doesn't attach to the inkling model, I don't know why since the jacket worked perfectly, can you help me please?

I don't have any idea for how this works so I can't try to deduce how I can fix it...

Thanks!

Do the locking process again (drag the character's animset onto the hat's animset). Looks like the head bone didn't get locked as it should have.

引用自 R234：

Do the locking process again (drag the character's animset onto the hat's animset). Looks like the head bone didn't get locked as it should have.

Thanks for the reply! I will try to show this step by step so you may know what I'm doing wrong (I will record the process in a video if necessary)

First I drag the Inkling animation set to the hat animation set.
https://s29.postimg.org/gb90etdbp/Sin_t_tulo.png

Then I deselect the Inkling animation set because it causes troubles while attaching.
https://s24.postimg.org/pliov1x0z/Sin_t_tulo2.png

Now, I select only the bones that are locked here:
https://s28.postimg.org/t2rlit5e3/Sin_t_tulo3.png

And for last I move the Zero preset to the right... the results are the same and I tried multiple times:
https://s23.postimg.org/le2p58zfd/Sin_t_tulo4.png

The worst thing is making the exactly same steps for the jacket it works fine, here is a pic with the attached jacket:
https://s30.postimg.org/lw8a5wgb3/Sin_t_tulo5.png

I don't what is going on...

Hm, I think I might have an idea what the problem is. But just to make sure, could you show me the Inkling model's whole list of bones? Just expand all of its groups and snap a pic of that.

Yes of course!, Here it is:
https://s24.postimg.org/4mfmrv2n7/Sin_t_tulo.png

I think that's it, tell me if you need to know something more about the bones, however the only thing I found clicking to the other sub parts are "pos" and "rot" with "x,y,z", but I don't know what are they.

The hat doesn't have the same bone names as the Inkling model, thus there's no bone for "head" to lock onto (since it's called "bip_head" on the Inkling, not "head"), and as such it won't lock.

Right, it's as Zappy said. You'll have to lock the hat's head bone to the Inkling's bip_head bone manually.

Oh! That was it! I selected the bip_head from the Inkling model and then dragged that to the head from the hat and for last I moved the Zero preset to the right and it worked!.
Thank you very much you two, I wouldn't be able to do this without help! :D
I will try to do the same with the shoes.

OK, this is really difficult, I tried even a new jacket and now that I see the bones they are completely different than armor_jacket1, is like every cloth has different bones and I can't attach them...
How I can know what I need to attach? Because this jacket has different bones than the armor_jacket1
https://s30.postimg.org/e86ep3h7j/Sin_t_tulo.png

And yes, I tried the both methods from before, but they don't work.
It's a little desperate for me, since in gmod the bonemerging was a lot easier and the other jacket merged to the inkling model really easily...
Sorry to keep asking things about this.

EDIT: I will record this now to show exactly what I'm doing, since now I found all the bones to attach, but I don't know why it's not working.

EDIT2: After trying a lot, I get to improve a little with this... now the new shirt attachs to the model, however... it's not very good:
https://s23.postimg.org/7gz6km3t5/Sin_t_tulo.png

EDIT3: Well, here it is my full process, I hope you can see what I'm doing wrong now, at least it fits the Inkling model...
https://drive.google.com/open?id=0B7cjlTRIUKXQZjM3V2pCQzR5SDA

It can't have worked on its own in Gmod if the bone names don't match, at least not with these models. Maybe they're from a different pack that's not meant to be compatible? Either that or the author royally screwed up.

There was a long time that I don't use GMOD, I tried right now and some clothes bonemerge and others don't... However, in the video I posted I'm doing the process correctly? So this way I will know when a clothes is correct for the model and when not.

EDIT: It seems some clothes aren't compatible now because there are 2 versions of the Inklings, 1 is an improved version (which is what i am using) and the other one is the old version (Now It's deleted from the workshop).

I will try with another thing and see if I get it working

Okay, I know why it's not working, the models are NOT compatible with each other, I tried that in GMOD and it's NOT working, that was the problem, now I'm using clothes that are compatible in Gmod and that is working in SFM as well.