Changing hyfax is incredibly easy. Start by suspending the rear end or turning the sled on its side. Loosen the track tensioners and looses the rear wheel axles, sockets will work. this will allow the track to be loose so that you can work down there easier. There are 2 screws towards the front of the rails, right about where they starting turning up towards the front of the tunnel. I believe they are T25 Torque screws. These hold the hyfax on (kind of). There is one screw on eash rail. You will need to roll the track around so you can see them through one of the windows, and take them all the way out. Once they are out the battle is trying to get the hyfax off the rails. If you have a paint scrapper or a chisel you can start by tapping it backwards from the front until it starts hanging over the rear of the rail. As you get it moving off the rail you will need to roll the track to make sure you can pull it out one of the windows. If you can get it out one of the windows then you can get a pair of vise grips and start pulling, sometimes they pull straight off and some time they are a battle. Get them out, put the new ones next to it, mark it, cut it (hack saw, or table saw) remember to cut it at an angle. Reverse process. they generally slide in easier than out. Put the screws back it, tighten rear axle and tensioners. Done. Can be done in about 10 minutes, half hour at absolute most. Good luck
