Does anyone know an easy way to change grip position on a tool?

I have the tool made and everything, I just need to gun to go where I want it. Grip positioning is making it go in weird places, while some of them aren't even moving at all. Is there an easier way to do it?

The absolute easiest way to do this is use a plugin made by Anaminus called Tool Grip Editor. This conveniently allows you to adjust the grip position of any tool the same way you would move a brick with the studio tools.