have trans out of a 85 camaro how do i replace rear main seal

 

Drop the oil pan, remove the oil pump, remove the #5 rear main, snake the block-side half of the seal out around the crank journal, push the new block-side seal in (specialized plastic tools for removal and insertion are available) and replace the cap-side half staggering the ends so they don't align with the cap-to-block parting line, reinstall the #5 rear main with a small amount of RTV in the corners and a tiny amount on the seal-ends, reinstall oil pump, replace the pan.