Not that bad. Have done mine (Viper) twice now. Budget 3-6 hours depending on issues and experience.
Pull the suspension. Remove the secondary clutch, along with the speedo sensing unit (2 bolts), speedo gear (bolt on end of shaft) and the remaining 2 bolts. My shaft would not pull through the bearing, so after failing to locate any burrs, I ended cutting off the rivets with a dremel tool as well. Not nice, but it allowed the bearing and retaining plate to come out with the shaft. On the other side is where things get a little messy. Remove the exhaust can. Remove chaincase cover, and soak up the oil. Back off the chain tension. Remove gears and chain. Remove the air deflector for the brake rotor. Unbolt the calper. Remove the emergency brake. Note: remove the bolt holding the coolant hose so you can pull the hose away from the chassis... this will enable you to tap the bolt holding the emergency brake back towards the footwell. Don't take it all the way out... just back far enough to remove the first spring. I leave the second in. By just removing the first spring, you can pivot the emergency brake lever/pad up and out. Now remove the entire back of the chain case (4 bolts). Once the chain case is pulled away from the chassis, you now have the 'play' required to move the drive shaft out of the bearing on the secondary side of the sled. Swap the track and reverse the procedure. Good time to check everything while its apart. Only trick going back in is regarding the suspension. Loosen the bolt on the end of the control rods. It will allow you to line up everything a whole lot easier. Can't comment on the SRX... but it should not be that different.
I thought about trying to leave the chain case in and just pull the 'c' clip and bearing on the drive shaft, but didn't think there would be enough play to pull the drive shaft back, then angle it to get the track out. If you could, this would save a hell of a lot of time (i.e. back of chain case and emergency brake stays untouched)
Anyone who races or just changes tracks for the hell of it want to correct me... or add anything?