EDIT: Just realized that what I wrote is a bad idea since you make the changes directly in the Conqueror esp, you want to do them in a patch that overwrites Conqueror. Let me see if I can think of a better way.
EDIT2: Here is an amended version that I haven't tried - but I think it should work:
Which faction pack are you editing? Here's a quick example of how you could apply your character's face to one of Jammer's Gang Raiders:
View attachment 8614
1. First you need to make a patch for Conqueror, meaning you need to flag your SimSettlements_XPAC_Conqueror.esp as a Master file in the header in FO4Edit. Keep the file extension as .esp
2. Here I'm a bit unsure, since I do most of my editing in the ck, but I think you need to Copy as Override any kgConq_Enc_RaiderFace_FemaleXX and kgConq_Enc_RaiderFace_MaleXX that you wish to change.
3. Save your Patch.
Then:
1. Download FaceRipper (and probably read up a bit on it, if you haven't already).
2. Load up YourPatch in the ck, in the Object Window filter for kgconq*enc*face. You will now see all the faces that the recruits use. Note down the FormID numbers of a few faces you want to change in the second column.
3. Load up FaceRipper, in the first dropdown, locate the save where your character has the face you want to add (under Documents/My game/FAllout4/Saves)
4. In the second dropdown, choose 7-Player
5. In the third dropdown, find the esp you want to change under Fallout 4/Data (YourPatch.esp)
6. In the last dropdown, find the formID you wrote down earlier. The first two figures are related to load order and probably won't match.
7. In your Data folder there is now an esp YourPatchXXXXXXX.esp where xxxxx is the formid. This is the esp with the new face, so delete the esp without xxxxxx (or move to a safe backup place) and rename the xxxxx version to regular old YourPatch.esp.