This is a pretty good descrition of the procedure for installing the flywheel,
clutch disc and pressure plate with the engine out of the car...
https://www.youtube.com/watch?v=qFXhTR-epws Getting the clutch centered is the key to a successful gearbox install... and
don't let go of the gearbox until you have a couple of the top bolts in place.
Letting the weight of the gearbox hang on the input shaft is not a good idea.
Use a jack or blocks of wood to support the gearbox at the correct level if
you are working on your own.
Refer the the Toyota Factory Service Manual to get the correct torque values
for the flywheel and pressure plate bolts.
Cheers... jondee86