As promised, here is a quick tutorial regarding character model swapping.
Credit goes to Kra of course!
Firstly, you'll need AFS Explorer -> http://psoskins.jimdo.com/tools/
Open AFS Explorer and click "File" -> "Import AFS file" and load "plZsmpnj.afs" (can be found in your PSO/data folder)
You will see a list with 433 bin files, which can be divided into sections for each class.
Extract them all by hitting "Action" -> "Export folder" and choose a destination f