I'm trying to edit interest income from my credit union, but when I hit the edit key it takes me to list of financial institutions like I'm trying to add one.

Form 1099-INT reports interest from banks, brokerages, and other financial institutions. Here's how to enter a 1099-INT:

1. Open (continue) your return if it's not already open.
2. Inside TurboTax, search for 1099-INT and select the Jump to link in the search results.
3. Answer Yes to Did you receive any interest income?
   • If you see Here's the interest we have so far, select Add interest income.
4. On the following screen, select how you want to enter your 1099-INT (import or type it in yourself) and follow the on-screen instructions.
   

The name was already there, but it wouldn't let me edit the amount.

You can try deleting the entry and reentering manually

That's what I ended up doing yesterday.