Hey mate.
I have a commy in just now I was going to teach you how to change them.
I always press mine in with a vice and remove them with some tools I've had made up. The tricky part is getting the axle out as commencal use a sealing compound.
If you take your back shock off and run the back end gently through it's travel you can tell the condition of the bearings. I agree with bren you need to make sure you don't damage the bearing always press them back in using the old bearings as they're the exact same size.
I have custom modified performance bearings for the commies I can sell you a kit at a discount and teach you how to install the bearings as well.
Anyone else need a hand servicing their frames let me know.
here's how to check your bearings.