To uninstall Modo Plugins on MacOS you need to remove the files in 3 locations:
1. In /Applications/modo.app/Contents/Resouces there are 3 files:
SimLab.cfg (Needed by other plugins, only remove when there are no other plugins).
SimLabPDFExporter.cfg (The PDF plugn menu).
SImLabPDFExporter.py (Button Actions script).
2. In “/Library/Application Support/SimLab Plugins” there is a "Modo" folder.
This folder contains the the actual plugin files, and can be removed without issues.
3. In "~/Library/Application Support/", some plugins create folders like "SimLab PDF From Modo" and such.
These folders contain user made templates and other files, You can safely delete them.