I bring to you the "Dota Tool Kit v3.3c" by crisgon (Work in Dota v6.75)
Run as a administrator if you are having troubles.
FEATURES:
Remap:
-Inventory
-Mouse Wheel
-Skills , Selfcast and Autocast
CustomKeys:
-A quick and easy customkey generator (remember to check "Use customkeys" box)
Link download: Dota ToolKit 3.3c (DTK works 6.75)