Bought an underdash tray a month or so ago but needed to trim it so it would fit coz of my immobalizer. Ide got it all sitting well now but dont know how to mount it?

I remember seeing a post a little while ago but cant seem to find it. Just wondering what sort of brackets and fitting i should use and where. Any help would be great!

There was this post:

http://www.aussieveedubbers.com/forum/viewthread.php?tid=37393&page=1#pid341126 

thanx, i couldnt find it using the searches