Changing WordPress “admin” User in Multi-site Installation

I ran into this problem recently, and found this helpful post regarding how to fix it:

Update: Apparently that post no longer exists. I’ll see if I can find another one to replace it. I honestly don’t remember what exactly the old post had that I found so useful, but hopefully I can find another one that is also useful. 🙂

Update 2: Here’s the new one: