If it's installed correctly then I definitely can't help. Fairly new to this myself, but figured if it was an issue with installing it properly I might be able to.
Just because it can't hurt I'll just walk you through the steps I took to make it work just fine.
1) Download and extract leglayermove
2) Start the game via the loader
3) Load animtools
4) Load the attached position
5) Outfit the girl with the vanilla Overknee legwear
6) Load leglayermoveV1.swf.
For me it changes instantly.
If that doesn't work it's something I cant help you with. If so I hope someone else can.