But how? Iv looked at appendix 2, but their diograms suck for what i want to do... some pics below

If you look hard you can see some red marks indicating the part i want removeable, but whats the best way to do this that keeps it tidy, its to let people into the back, just take it out when not on the track, but the easyest way to do so that i can see requires alot of space..., and i dont want that much sticking out from each end.
also, how to do the X removeable in the back from the points showen in red....

Buy you all a bourbon when i goes