Installation instructions for a surface mount lock?

I ordered a slam-type latch for my trailer door from Fastec, and it didn't\\ come with instructions or a template, nor are there any on its website.
It looks just like the one Dean_A has at the link below. Any tips or instructions?
viewtopic.php?f=21&t=33079&p=591113&hilit=fastec#p591113
It looks just like the one Dean_A has at the link below. Any tips or instructions?
viewtopic.php?f=21&t=33079&p=591113&hilit=fastec#p591113