Freezer Door Lock Assembly

Hi, I’m looking for some advice or assembly instruction on how to install a universal lock on a Gibson freezer.

The part is located here

http://www.appliancepartspros.com/part_details.aspx?image=1&part_id=2584296&pn_=5303925437

However I’m unsure of how to remove the old lock and install the new one.

Anyone know where I can get a PDF or written instructions on this?