Well initially, I thought, "simple question". Until I went into my sample file to play around in it and found it is a bit confusing. So, here is a video:
Basically, the directions can send you down a bit of a rabbit hole. So, in the video, you will see if you add the 3rd user (or 2nd company admin), you will then be able to delete the first company admin.
We hope that helps clarify the issue for you. If not, please ask more questions.