I installed this in my sons 2003 Avalanche, not the easiest part to get to, but I pulled the main fuse and disconnected the battery, if you take the three bolts out that hold the part to the frame rail you can move it about 1/2 inch that gives you room to remove the four T25 bolts that holds the part to the top of the valve assembly. You can’t see them but you can reach over the frame rail to take them out. It has three electric plugs that have to be removed and the part lifts straight up and off. The new one goes right back on and has a built in gasket. It’s goes back the same way you took it apart, really pretty easy. Took me an hour, and most of that was figuring out the T25 size on the bolt heads. I put the fuse in and connected the battery. The truck was started and the ABS and brake lights cleared and the brakes work as they should have. For what a shop would charge it was well for it to buy this part and change it yourself. I changed the part because it would still run when the truck was off. I had to remove the square fuse under the hood to shut it off.