For 2.2.0, you can just run the new installer. Or, to remove it, you can uninstall it from in the control panel.
For 2.1.1, 2.0.0 and the beta, there should be something in the control panel to remove. That should uninstall it. If it installed both 2018 and 2019, then you will need to manually remove the 2019 one. The folder layout for that I will get back to you on. These versions were never released for 3ds Max 2020, so if you use that, then you needn't worry.