I'm about to replace my warn clutch, what else should I replace while I'm down there?

So far I've grabbed the obvious clutch disk, pressure plate, and TO bearing. Also an evo flywheel,a rear crank seal, and the three tranny seals. Should I replace an engine bearing at the same time?

Now come the novice questions:

Do I need to drain the oil out of the engine and transmission before I change the seals?

Do I need a special tool to remove the seals, and how do they install?

Thanks for any help given,
George