Quick overview on HPL2 Animation

[Daemian]

Here, I took the angel statue. I put the joints then did the bind thing via Skin>BindSkin>SmoothBind.
Then when I try to move/rotate the foot joint, she takes half the pedestal too.

Spoiler below!

So I go to Skin>EditSmoothSkin>PaintSkinWeightsTool and nothing happens.
I get the brush cursor but I can't click anything. How is this tool supposed to work? What kind of spell do I use?