Well you could download them in attachments posted by members around the forums, OR you con goto the tab at the top names ""Scripts"" and just find the script your looking for.
It will pop up in the browser so just copy and paste it into a notepad file (NOTE these are instructions for Windows users)
Once copied into the notepad file, save the file Into your toribash scripts folder, If you dont know where that is follow the path below as instructed:
(My computer > Local Disk > Games > Toribash _.__ > Data > Scripts > -Save it here-)
Then Open toribash and goto Setup > Scripts > Open your script
There ya go! You've Just installed a script.
I suggest using the forums for newer scripts because I dont know how often they update the stuff in that tab, but until you ge orientated enough with the forums use the tab.