[cassio]

You have to remove the oil pan, this will give you a hint of what's involved.

http://www.cygnusx1.net/supra/library/TSRM/lu/LU_07.html

I dont know if I read the thread correctly, but For the front main seal all you have to do is remove the radiator, thermostat housing, the top timing cover, the AC compressor, all belts on the Crank Pully, get a 19mm deep socket and a nice wrench w/ some leverage and pop that bolt loose and use wiggle the pulley lose, and use a puller for the timing belt gear, the seal is right there, use care and a flathead and pop it out, while ure that far in replace the tensioner, and the timing belt and the cam seals and other oil seal in there while you're at it... +1 point for me because i changed tht one week and had to replace the lower belt pulley the next week. If you're a novice give yourself a full day to do this job correctly, and make sure you set you timing back per the TSRM when you put everything back together.... have fun w/ your Supra.

-Ian