Severance offer, what should I ask for? - 9 months and counting

My manager said the package is final, but the letter gives me time to review. This is my first time dealing with any of this. There is a non-disparagement clause. Did anyone negotiate and succeed?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

Read the release carefully. Mine included things I did not expect, like a non-compete.