NOTICE: Our WHMCS Addons are discontinued and not supported anymore.
Most of the addons are now released for free in github - https://github.com/jetserver
You can download them from GitHub and conribute your changes ! :)
Login to your WHMCS as admin user, and navigate to “Setup” -> “Addon modules“.
Find the “WHMCS Invoice4U” module, and click “Deactivate“.
To completely remove the files, delete the folder: modules/addons/invoice4u.
**Deactivating the module will drop all the db tables and all the module information will be lost**