adding a spool gun to my mig

[joseph_zlnsk]

I am interested in adding a spool gun to my century 145 amp welder. Does any one know how to do all the wiring. It looked like at one time Br welding made a kit and no longer makes it. Looks like its just a switch I'm assuming to shut off the machines wire feed motor. They have 6 or so wires in their switch in their picture. Any help is greatly appreciated