Heya, That version uses the Patcher to add characters, manually using is not an option.
You need to point the patcher to something like ....Steam\steamapps\common\Knights of the Old Republic II. KSE only sees the vanilla stuff, so you'd have to start a new game.

Another option is to use my Steam version of the mod. It replaces heads (should work next to TSLRCM) instead of adding them and it doesn't add the special clothing. If you go that route you can use KSE to change your appearance.

Hi Effix, love your mods. I was told to avoid Steam for TSLRCM, so I moved to using Deadly Stream. I tried to install "TSL Effixian's Twi'lek PC Pack 2021 1.0.3." When I ran the .exe TSL patcher, it didn't work. I've tried to solve it myself, but failed. Is there a way to install manually? Also, is there a way to switch to this new head and portrait mid-game by using the Save Editor? Which appearance should I set my character's appearance to in the editor? Thanks.

No, sorry. Look into the mod Party Swap.

could you make a mod where handmaiden is a companion option for the female exile and vice versa with disciple?

I'm open to hearing what your request is. It's more practical to contact me on Deadly Stream or Discord.