I am attempting to mount the backhoe subframe on my L2550 and have a couple of questions. The place where the front mounting bracket goes has 4 threaded studs coming out from the bottom of the tractor, I removed the mowerdeck mount from this location but the 4th bolt is much longer than the others. Is this longer stud just able to be unthreaded and replaced with a shorter stud. Also I need to remove the 3pt arms to mount the rear mount bracket, I have removed the bolt and square tab that hold the pins in but I can not get the pins out, are they threaded in or just pushed in, thanks for any help .