I used this method on an old Estes Executioner. I cut at the seam using several wraps of card stock as a cutting guide. Once the tubes were apart, I peeled most of the coupler out. I then used a dremel with a flex shaft and an 80 grit flap sander to get the rest of the coupler and glue out.Might be able to cut on the seam and peel the coupler out of the inside. Not sure if the body tubes are robust enough to handle that.
I commend your effort but gotta wonder if it would have been quicker and cheaper to build another one.....I used this method on an old Estes Executioner. I cut at the seam using several wraps of card stock as a cutting guide. Once the tubes were apart, I peeled most of the coupler out. I then used a dremel with a flex shaft and an 80 grit flap sander to get the rest of the coupler and glue out.