To completely remove your plug-ins from a Mac, remove the relevant plug-in files from these directory paths: -

VST

HD/Library/Audio/Plug-Ins/VST

AU

HD/Library/Audio/Plug-Ins/Components

AAX

HD/Library/Application Support/Avid/Audio/Plug-ins

RTAS

HD/Library/Application Support/Digidesign/Plug-Ins

MAS

HD/Library/Audio/Plug-Ins/MAS

Then, also remove the folder of the Manufacturer from both...: -

• HD/Library/Application Support

• HD/Applications