Pretty easy to switch to a manual, I did it in my 85.
Add cltuch pedal, brackets already there.
Add master cyl, you need to cut holes in the firewall for it.
Add your manual trans, clutch, etc.
Cut holes for the shifters
Jump the neutral safety switch.... you'lll find one on the plugs to the trans has 3 wires... two are thick black wires, they need to be cut and soldered together at the frame end of the harness, otherwise it won't start...