Hi @markknecht !
The uninstall app is the same as the install app.
You can find it in the Steinberg Download Assistant Download folder.
Choose the “Uninstall” option. Make sure to do this for all entries where it says “Already Installed”
On the next page, You have to (unintuitively 
) click “Install” to confirm on the next page.
You can also go via the Windows Programs and Features or use @raino suggestion, but this might leave a few files, unmanaged by MSI, on your system.
Would be interesting to know what issues you ran into or if you could fill out the survey (if you haven’t already):
Thanks.