The bearings are not pressed in, they are held in place by a lock ring. There are lots of videos and photos in the how-to section of the site that will walk you through the complete rebuild: How to Rebuild a T20

For your bands, if the metal of the bands are in good shape, you can have all four relined for about the price of one new one. Use the search here in the transmission forum to find the contact information for the companies that reline them. Many people, including myself have had good luck with Transmission Crafters in Albany Georgia.