Installation Guide
TorrentBD Theme Engine is offered as a UserScript. So, you need a UserScript manager to install it.
1.Script Manager
The script was developed using TamperMonkey on Firefox. If it is available for your browser, please install it from its website.
If it is not available, alternatives like GreaseMonkey and ViolentMonkey may also work, though they haven't been tested.
2.UserScript
The script is only released on GreasyFork for now. Head over to the script page to install it.
You need to have a Script Manager installed for this to work.
Uninstalling
If you don't understand how TamperMonkey works and only installed it for this script, go ahead and uninstall the extension.
Otherwise, you can disable the script from TamperMonkey's dashboard.