reinstalling vs buying new chain
I removed my chain using a chain tool, completely drilling the pin out of the plates. I'm realizing after that it is very tough to get the pin back into the plates. Am I screwed, and having to get a new chain?
You're probably OK.
First measure 12 inches of chain. If the first rivet after the 12" mark comes at 12 1/16" or closer, push out the other rivet in the same link and replace it with a Sachs power link. If your chain shows more stretch than that, it's time for a new chain anyway.