Iv'e done it to a couple car's that I had. Go to a store that sell's stuff like diesel equipment or farm equipment, etc. And measure from your dash ''or wherevr' you want the knob to the firewall.......down and underneath to the tranny where the lingage arm is on the trans. Then go get a heavy duty push/ pull cable ''like a PTO' CABLE. You run it from the dash and down to the tranny. You will have to make a couple little brakets to hold the outer cable stationary and the inner cable will be able to slide easly. Then just figure which direction the cable need's to run...... usually it's running from the back of the tranny to the front. Make or adapt the little lever that is attached to the side of the tranny for the shifter. And once you get it hooked up, be sure to hook up a nutural safety switch. Then get a knob that matches the other knobs on your dash..... or just leave it.
It takes a little adjusting on the linkage end...... but it's really basic stuff.
PS. Try to avoid any tight bend's........ the straighter the cable....the smoother the cable slides.
Hope this makes sence to you,,,,,