Taken from Autodesk documentation
Uninstall via Control Panel / Settings
Revit 20##
Autodesk Material Library 20##
Delete via Windows Explorer, if present
C:\Program Files\Autodesk\Revit 20##
C:\ProgramData\Autodesk\RVT 20##
C:\Users\%USERNAME%\AppData\Local\Autodesk\Revit\Autodesk Revit 20##
C:\Users\%USERNAME%\AppData\Roaming\Autodesk\Revit\Autodesk Revit 20##
All contents inside C:\Users\%USERNAME%\AppData\Local\Temp
Do not delete the temp folder
Skip for any contents currently in use
Delete via Registry Editor, if present
HKCU\Software\Autodesk\Revit\Autodesk Revit 20##
HKLM\SOFTWARE\Autodesk\Revit\Autodesk Revit 20##
HKLM\SOFTWARE\Autodesk\Revit\20##