Repairing Piers and Beams

[RTK]

After crawling under my house to fix my plumbing problem I discovered many more problems. Years of water damage destroyed the subfloor of the bathroom and I'm in the process of fixing it now. My biggest problem though is the termite damaged floor joists and misaligned piers. At least ten floor joists need to be replaced along with the board that they rest on (the one that rests between the joists and the foundation wall). Some of the piers that support the beams no longer sit directly under the beams and have shifted two or three inches to the side, this is pretty scary considering the contact surface of the top of a pier is six inches max. Also, the shims used to level my house are wood, scraps of plywood in some spots. I had a house leveling company look at my house and they said it didn't look too bad, being as old as it is and sitting on top of clay. They did point out the wooden shims and said that they use metal ones because they don't swell with moisture. My questions are: How do I replace the board that rests between the joists and the foundation wall? How is it secured to the foundation wall? Where do I find metal shims? Can I shift the piers back into place? Can I install new floor joists without tearing up the floors?