[boiow]

it says on my backstrap instructions. If the cartridge won't come out , loosen the other two hex keys. mine come out easily.

 

[harley]

Isn't there a little set screw that holds it in. I used to have one but don't remember.

 

[rogbo]

There are three or four hex screws on the flat of the release. Take out the two where the cartridge slides into the release head. If the cartridge won't come out then loosen (don't take out) the two further away from the cartridge. If it don't come out then........get a hammer and "convince" it. Just kidding about the hammer. If it doesn't come out then, there may be some dirt or grime holding it up. Gently manipulate the cartridge with the tip of a knife and it will pop out.