what all is needed to do when changing auto trans to standard trans on a 1996 vw jetta gls

Best off to get a doner car that way you have all the parts. Not a VW guy but here some info to start I am not familier with ECM tuning for VW's that old, but I am getting there with GM's and the basic engine controls are the same. The main issue would be the decel. When you let off the gas on an Auto vehicle the tranny keeps the engine RPM up, on a manual vehicle there are special tables to move the IAC when the clutch is pushed and the throttle cut to keep the engine from losing to much rpm. Also the safety start features are different P-N safety vs Clutch. 1.) ECM, interior and underhood wiring harnesses. 2.) Cluch pedal, clutch system, mounting bracket and all safety switches. 3.) Tranny and cv shafts and shifting mech with cables. On the OBD1 GM's I mess with I just need to swap the chip in the ECM hope it's that easy for you. I could also just modify the harness and re-pin the ECM but I hate adding connections, I just swap harnesses. Good Luck. Anyone with more VW info, help him out. Thanks