i have a 90 auto cefiro and swaped the parts out of a 32 skyline. please excuse all spelling mistakes.
1 disconnect battery
2 unclip gear stick surround and unbolt 4 bolts holding gear leaver to chassis, unplug all plugs. go underneath and unbolt and unclip where gear leaver mounts to gear box.
3 drain oil out of gear box
4 undo 2 top bolts holding trans to motor, difficult long 14m spanner helps, remove top bolt out of starter motor
5 jack car up, remove drive sharft, pipe which holds dip stick into trans. cut the two pipes which carry fluid from the trans to the bottom of the radiator. release all cable ties which hold the 3 cables which go to the trans and un plug from box behind battery.
6 undo rest of bolts holding motor to trans. support trans and unbolt cross member. jack up the front of the motor with a block of wood on the sump, spin trans slightly so that starter motor casting is facing down, pull trans off motor an onto floor
7 unbolt torque converter ( 3 14mm bolts on motor side of fly wheel ) and unbolt fly wheel.
8 remove old spigot bush, i drilled mine out with a small drill bit, and install new manual spigot bush with a hammer and a piece of wood. $20 from nissan. bolt on clutch. check oil level in manual gear box.
9 slide box on in much the same fasion as you slid the old one off. drill out cross member to fit mounting holes, apparenty a s14 manual one fits. bolt cross member up and onto box.
10 get drive shaft made to length, or un bolt the 32 drive shaft at the centre universal and swap over flanges from your auto drive shaft. ( very hard to do, got a mechanic to do mine $20 ) bolt the front 32 drive shaft with the auto flange to the rear auto drive shaft. install whole drive shaft.
11 remove foot hand brake and bend air con duct out of the way, slip clutch peddal in and bolt up ( easy, not as every one says ) bend air con duct back. go to engine bay and bolt in clutch master cylinder. my doner car had hicas which interferes with the hydrolic line for the clutch, so i brought 2 14mm bolts and plugged up the holes in the block where the clutch lines goes through and used all skyline brackets and clutch lines. grind off brake peddal to sensible size. bleed clutch at master cylinder first and then at slave cylinder.
12 plug the cable back into the box behind the battery which has only 2 wires and join the 2 wire together, this is your inhibitor. connect back up battery. job done
i have not hooked up reverse lights yet or installed a hand brake. hope this has helped, any in put will be greatly appreciated. installing rb26 next, any diagrans on how a rd 20de computer is wired would be lovely, just lovely