I didn't see clips, the head seems to be securely anchored to the two horizontal tubes which are themselves securely anchored to the frame. Is it possible that the clips are on later model Beselers?
I think the clips have been a part of the 45MX enlarger design from day one. You are confusing the horizontal round supports for the whole head. You need to look closer.
The Enlarging head consists of a light source (in your case Dichro head), then a bellows (which may be completely compressed, or removed) leading down to the Negative stage, which opens and shuts with a lever, and below this a bellows leading down to the Lens stage, where you put your enlarging lens.
Just below the light source (your Dichro color head), but above the negative stage should be two little horizontal strips of bright metal one on the left and one on the right (if you are facing the enlarger) They have little L bends at the ends facing you. You put your fingers behind these L bends and pull the metal strips toward you..they slide forward..they may be tight if they haven't been pulled in a while. They WILL move toward you. Once they have moved toward you, the Dichro head is released, and by grasping JUST the Dichro head, nothing else, and lifting straight up, the head will separate from the rest of the enlarger and can be set aside and transported separately. One of the features of all Bessler 45 series enlargers was the option to have many different styles of light sources easily interchangeable, such as condensor, point source, cold light, color head, etc. You can remove this head, I know you can do it. Look close. Remember you don't want to remove the whole enlarger head, just the light source..the Dichro head