I can not guarantee that this will work with every device/rom but it should on most! There are several reports of issues with TouchWiz based ROMs
Module is now available under Downloads in the Xposed app itself. Please Download it from there!
1. install http://dl.xposed.info/latest.apk
2. open app click "Framework" and "Install/Update"
3. click Download and choose XVolume
4. click Download again and install app
5. click Modules and tick XVolume30
4. open Xposed app and go to "Modules"
5. tick XVolume
If it dosn't work for you please post me your /data/xposed/debug.log here.
UPDATE: Simple UI added. Remove old app before installing the new one in Setting->Apps please.
Original mod without xposed (but a little more tricky) http://forum.xda-developers.com/show....php?t=2326333