Picture would be helpful.

I found it easy to slide the scope free without the possibility of damage by wrapping a thin piece of sheet brass the right size and holding with tape. You can make the tape long enough to ride the total distance. you can save the brass tube to use again, and adjust for different diameter tubes. A beer or pop can will work in a pinch, but more likely to drag on the softer aluminum. I do the same when removing the eyepiece to access or remove the reticle cell to work on replacing the crosshairs.