Engine Coupler Repair

I have three Bachman N scale engines that have the couplers missing on them and i can’t for the life of me figure out how to replace them or if there are any special tools out there for this. Anyone got any ideas? Thanks!

Josh

were they rapidos or microtrains? were they body mounted or truck mounted? if they were microtrains they make conversion kits for just about every n scale loco… if they were truck mounted rapidos they just twist in and then the spring is added behind it. you could just cut off the coupler pocket on the trucks and install body mounted microtrains but you will need the drill and tap set for the mounting screws