Like with WHMCS itself, the majority of WHMCS User and IP Control is able to be localized. The English language file in modules/addons/ipextended/lang will help you get started there. There are a few non phrase definitions in there that you may want to change
- Date Display
This will change how the date is formatted for you and clients. There are two separate areas for this - Colorization
Primarily for menus, this was designed to allow better control over the look and feel of those - Icons
The fontawesome icon library is huge, the ones we put in there may not be the ones you want, so feel free to change those