Bartender 3

To Remove Bartender you can simply drag Bartender from where you installed it to Trash.

If you want to remove all files related to Bartender you will need to remove.

Bartender.app from wherever it was placed, most likely Applications.

/Library/ScriptingAdditions/BartenderHelper.osax

~/Library/Preferences/com.surteesstudios.bartender.plist

And if it exists:

/System/Library/ScriptingAdditions/BartenderSystemHelper.osax

Bartender will then be completely removed.