Trimming teh shifter knob. (93 Sentra XE)

Tomarrow I'm planning on seeing if I can cut my shifter down a few inches.

I'm gonna see if I can cut it, then thread the metal so that I can just screw another knob on there that I can just buy.

I was just wondering if anybody had any idea what kind of tool I should get to thread the metal.

I'm gonna ask some friends too, but I just figured since it's the middle of the night might as well ask you guys!

Any suggestions = helpful!