Visual Studio removal (of old versions)
Removal of (older) Visual Studio installations is possible using the Custom Software feature.
Select the right "bootstrapper" for your use case / license (new ones can remove older installations):
All you need to remove a given installation is to run it with these parameters:
uninstall --quiet --wait --installPath="C:\Program Files (x86)\Microsoft Visual Studio\2017\Community". This will automatically remove the installation in the mentioned folder.
It is important to pay attention to the path, even an extra trailing
\will cause the operation to fail.
You also need to consider if the old installation is 32-bit (x86) or 64-bit.
If you supply the wrong path, no harm should happen, the installer just fails to remove Visual Studio.
If you don't supply the "installPath" then it will remove all Visual Studio installations.