Athearn 40' HiCube Box Car Coupler Conversion

I am trying to convert the McHenry couplers on the HiCube to Kadees. If anyone has done this, how do you remove the gearbox cover? It is NOT attached with a screw.

Athearn used to use metal clips for this. There should be tabs cast into the box that the hook over. Use a thin-bladed screwdriver or knife blade to pry them sideways to pop off.

If it’s something else, it’s likely just glued on. Carefully pry it off, then drill to accept a cover with a screw, drill and tap as needed.

If this is the RTR model, then it is glued on. All you can do is either try to pry it off or, using an x acto knife, try to slice through the glue joint.

I’m not sure of any other way to do this. Good luck!