Thanks Dan,
To clarify --It is safe to say I own the data. That is not an issue.
I can go all the way through step six. Basically, I make whatever changes I want to the layer in Pro, save it, then on the share tab click Web Layer > Overwrite Web Layer. Then, a warning pops up explaining that I am going to lose whatever changes may or may not have taken place to the web layer online (not an issue) and I click OK. Next, the Overwrite Web Layer pane pops up on the right. All of the metadata is already filled in with the previous version info. Configuration settings are unchanged. That's as far as I can go because the Analyze and Publish buttons are grayed out.
The web layer exists in my ArcOnline account in a subfolder under my main directory. This is where the layer was originally published --in the subfolder.
Thanks,
Phil