Download Vackle
For the Flackle desktop app. Version 0.4.22, one signed file.
Open Vackle.exe
It finds your Flackle install on its own.
Open Vackle in Flackle
Find it in Flackle's Settings, or press Ctrl+Shift+V.
Switch on plugins
All 48 are off until you want them. To uninstall, run Vackle.exe again.