Cirklon to Cirklon 2 Differences and Upgrade Procedure. 

A brief explanation of the difference between Cirklon and Cirklon 2, and the upgrade process for older units.
The unit upgraded in this video is the final hardware revision, with the IO board mounted on mounts that are internal to the rear panel. This applies to serial numbers 973 onwards.
I will post other videos specific to the other hardware revisions shortly.
Units with serial numbers from 328 to 972 are almost identical to the unit here, with the exception that the IO board is mounted to the rear panel with black hex screws that pass through the rear panel into L-brackets mounted on the board.
Upgrades for earlier units are a bit more complicated.