How to "downgrade" skype to a previous version

I just installed the upgrade to Skype and after 10 minutes I'm ready to go back to the previous version.  I don't have time to mess around with trying to figure out where everything is and I don't like the black background.

You don't need to do anything with the new Microsoft Skype for Windows 10 App (Skype UWP). The only what is required to close this app is sign out.

https://support.skype.com/en/faq/FA34668/how-do-i-sign-in-to-skype-for-windows-10

After you have signed out of Skype for Windows 10, the App will close and you can start the classic Skype for Windows Desktop, which should still be installed on your computer. Look for the desktop shortcut pointing to this Skype program or open it from the installation folder.

C:\Program Files (x86)\Skype\Phone\Skype.exe  (if your Windows is 64-bit)

or

C:\Program Files\Skype\Phone\Skype.exe  (if your Windows is 32-bit)

Actually, you can also just start and sign in to the classic Skype for Windows desktop, and this will also close the new Skype for Windows 10.

https://support.skype.com/en/faq/FA34694/can-i-sign-in-to-both-skype-apps-on-windows-10-at-the-same-time

In any case, if you still want to try the new Skype for Windows 10, but don't like the black background, then this can be changed using button.

https://support.skype.com/en/faq/FA34664/finding-your-way-around-skype-for-windows-10?platform=uwp?q=get+started

Any version of Skype below 7.31 has been retired so 7.22 is not an option.  You can still download and install the latest 7.x version of Skype Classic.