I assume you're talking the seals on the front and rear main bearings.
On the rear remove the bearing cap. The seal is in a groove in the cap, and you can push the old one out using something soft enough not to scratch the crankshaft. If you can, get a NOS rope seal, the older materials work better than the new.
If the front is like the later 216, you need to remove the harmonic balancer. There is an oil seal behind the balancer in the timing cover.
If you remove the cover, there are two bolts that go through the front main cap from the rear. To make it so you don't have to drop the pan to remove the timing cover, remove the bearing cap and tap the holes. Then open up those two hole in the cover, and put in bolts from the front.
Also, check the balancer shaft for grooves, it's unusual not to have any. Buy a redi-sleeve when you get the seal, it taps down over the shaft and gives you a smooth surface for the seal.
