Changing select key in Pro/E

Well, the question is as simple as it gets, i want to change the select key from middle mouse button. i know i can click the arrow, but that proves to be a drag. the reason i want this is because

  1. I use my mouse a lot, and the mouse wheel button has become a bit shaky, and i need to press it 3~4 times just to register 1 click

  2. Im using a gaming mouse Razer Deathadder, as im a avid gamer, i dont want to spoil the mouse wheel as it is important by using too much of the mouse wheel button, which loosens the wheel generally.

I have 2 thumb buttons, which i’d like to assign some command to, as its going unused and would be very convenient to use it.

someone help please.

buy a new mouse yo!

haha as appealing as it seems, i cabr afford 80$ on a mouse again.