I did a bit of Gmod hacking before when I was bored and there was nothing else to do. I can't make a YouTube video, but I can help you. Here's how you do it:
1. Download an injector, a bypasser, and a hack.
2. Put all of them in a file that you can easily access them, such as on your Desktop.
3. Open Garry's Mod and the injector.
4. You will see a list of applications, find Gmod and click it.
5. Click the button to select a dll and go to the file you created.
6. Select whatever bypasser you are using.
7. Inject the file.
Depending on what bypasser you are using, you will have to do different things to load it up. Just find out the commands for it and then load up your script. If you don't know how to do that, I can help you with that too.