Y- Remove Limb
H- Activate prosthetic (default)

To attach the limb in the first place, hover over the UPPER arm and press "Y" to remove it or alternatively rip it off using any other tool you please

then, simply bring the prosthetic over the empty arm.

Congrats it should be attached now and you can press "H" by default to activate its function

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Check your controls in the "Modded" section for:

"Specially activate object (SA) -MPW"
"Quick dismember & heal limb"

If any of these keys is highlighted in red, that means there's a conflicting mod using the keybind as well, change it to another key that's not in use.(You'll know because won't be highlighted in red anymore)


Subscribe to the MPW library at
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2953788932

Then, in the menu hit mods and scroll to or search for MPW Library

If it's marked as suspicious, hit "Accept risk" and enable it.

I had no more issues past this point so help the others under this discussion if there is something I have missed here.