How to avoid duplicates

If I add a facepack and then add another one and somehow there are two photos for the same player
how do I eliminate the duplicate ?

Most facepacks generally have the player's UID as the filename of each image. If this is the case, you need to find a duplicate file/image finding program which would locate instances where you have more than one image for the same player. You can then decide which one (s) to remove.

thanks so much