The first item I removed was the factory Y-pipe. It is straightforward and uses a 15mm socket.
Tip: Remove the crossmember before removing the Y-pipe. It'll make it alot easier to remove the Y-pipe and install the new one. The crossmember uses 15mm, 18mm, and 7/8" bolts.
Here are the O2 sensors. Several people have had to replace their sensors because they damaged them during removal. I must be lucky because these came out without any problems. They use a 22mm wrench.
Here is the factory Y-pipe next to the Borla Y-pipe.
Remove the air intake and EGR tube. The EGR tube needs a 1 1/4" wrench.
The exhaust manifold is removed.
Here is one of the studs that hold the factory exhaust manifold on. The nut is 1/2". If you're lucky the whole stud will screw out when you're removing the nut. If not, you have to screw the stud out with a 5mm socket. The studs screw out easily (after the manifold is removed).
Remove the oil dipstick with a 7mm socket.
The Borla header looks much better than the factory exhaust manifold. In fact, the factory exhaust looks downright pitiful.
The Borla header is set into place (from the bottom) and bolted into place. The supplied Stage 8 bolts use a 7/16" socket. The header is not hard to install. All the bolts are accessible, but some require a wrench instead.
I reattached the EGR tube and oil dipstick. The modified fitting worked like a charm. The EGR tube didn't match the new headers so I bent the tubing about an inch.