I initially balked at the idea for fear of rusty, scary bolts and nuts. But, thanks to a lift, and all tools I needed, the install went very well - 2 hours, even with me stopping to joke around and chat with friends there.
First I removed the heat shield. More bolts there (10mm) than on the turbo/downpipe itself. None were hard to reach. Along the passenger's side, there's one down there - a small wrench had it off easy. Feel around the casing and you'll be able to remove the heat shield from the top after you find the nuts (6 or 8 I think).
Three 14mm bolts hold down the TIMC - there are two off the turbo, and one on the upper right of the IC. Channel-lock pliers help the hose come off the BOV, and a screw driver to release the hose clamp around the intake inlet elbow thing.
Now that the IC is out of the way, you'll see two bolts/nuts there on top, with a bracket. Those are 14MM as well - loosen those, then find the nuts on either side. Reaching your hand around it's possible to remove all the bolts on the DP/Turbo from the top.
As an aside, sprayed them down the night before with PB Blaster. They were so easy to come off, I was shocked - just torqued nicely, no worries.
Now, get under the car. There are two brackets holding on the stock piece, on up near the trans, and another down on/near the cat. They are 14mm as well. Only the one near the cat will be re-used. While you are there use a 22 open end to loosen and remove the O2 sensor.
Where that pipe connects to the y-pipe, there are spring-nut things. On the nut side it's a 12MM, on the other side it's a 14. The way mine were angled I used a 14mm socket one and a 12mm wrench on the driver's side, and a 14mm wrench w/ a 12mm socket on the passenger's side.
When everything was off, I had a friend use a pry bar a bit to move the pipe off the bracket near the O2 sensor. Once that got bent a little the whole thing came down.
Compare - see what the WG opens into on the OEM? A metal plate. A wall.
As a pre-caution against the Invidia WG flapper-tapping, I grinded down near the top of the divorcer, to help ensure clearance.
The Happy Machine!
Just as easy, the new one went back up!
You can see the bracket towards the bottom there - down near where the two pipes are touching (but not yet lined up). That's the bracket we pried a bit to get the OEM pipe to drop. Also - there's one bolt you'll have to get from under - and you'll have to use a wrench. The way the pipe works, there's no clearance for a socket.
After everything was tightened up I took to grinding/trimming down the Heat shield. I WISH I had remembered to take a photo of it. I'll find a photo of a stock heatshield and mark where I cut it.
Now - everything is back together and I'm set! I get the whistling/chriping - makes me think there's an exhaust leak. But I'll work those out eventually. As far as sound? To me it sounds like a tractor now.