I'm sure everyone has got into an all out wrestlin match with a gear shifter collar..quarter turn and its out ....goin back aint so easy you got a concave lock and spring to collapes ...Channel locks just make you say some continential compound cuss words ... Today I face this challenge with thought ..new spring and new locking collar ..I used a wrench that comes with most small side grinders ..small spanner wrench you can push down and when turning the pinsof the wrench will lock the collar .. Cant believe someone aint invented a tool for them buggers ..
LoL, sounds like you just did invent a tool for it.
If you are talking about the underside of the shifter tower on an Eaton truck transmission, I made a tool by grinding a notch in the corner of a big cheap flat screwdriver. It works pretty good, but I'll try your way next time.