How do I uninstall the Pack Manager? – AEJuice
  1. Close After Effects
  2. Delete AEJuice folder from your Plug-ins folder, for example:
    C:\Program Files\Adobe\Adobe After Effects CC 2019\Support Files\Plug-ins” on Windows or
    Applications/Adobe After Effects CC 2019/Plug-ins/” on Mac.

 
These steps should completely remove AEJuice Pack Manager from your computer.