Resetting Garry's Mod

If its possible, I would like to know how to do this. Are there default files or something, so I can download them and delete my current? I have so many models and such, that it would take forever to delete them all.

Rename your garrysmod folder that contains all your addons to garrysmod old.

As in just my addon folder, or my entire gmod folder?

Entire gmod folder:
C:\Program Files\Steam\steamapps\steamname\garrysmod\garrysmod
That one so it’s
C:\Program Files\Steam\steamapps\steamname\garrysmod\garrysmod old

And this magically resets it? There is nothing else to it?
I will do that now, thank you for your help.

[editline]10:44AM[/editline]

I am expieriencing a problem. It tells me I need permission, even though I am the administrative user on my computer. Is there a way to fix this too?

make sure you are a computer administrator in control panel, or rename it in safe mode if that doesn’t work.