Stock turbo inlets suck, they are horrible for flow and tend to rip very easily causing vacuum leaks. Due to vacuum hose location I wouldn't suggest buying an STI inlet if you have a LGT version available, but with hard inlets you only have the STI's style available.
I personally got the Perrin STI/FXT/WRX2.0 inlet very cheap (had a tear that needed to be fixed), that's why I ended up using it. In the future I plan on making a custom LGT one though.
First remove the intake elbow
Then unbolt and remove the MAP, WG solenoid, and unbolt the bracket. Shown is the WG solenoid and hose routing (will come in useful later).
More vacuum hoses to remember, bottom most one is the EVAP canister one.
Remove them all, Valve cover breather is the big 5/8" hose still attached
Next unbolt the valve cover breather tube, removing the left heads hose helps you get it out of the way
Unbolt the BPV recirculation hose, this will help a lot to remove it from inlet, and will help to reinstall.
Remove PCV valve cover breather 5/8" hose
Pull the wireloom back to expose the PCV "leak detector", this is the last vacuum hose on the stock inlet. It's a little tricky to remove the plastic PCV "leak detector", the pigtail is what locks the leak detector in place.
This will expose the BPV clap, tricky one to remove. You will need to use pliers and pull on the hose to wiggle it out.
Unbolt the inlet from the turbo and finally you can pull the stock inlet out.
I dunno why people complain about room, plenty of room here for 3" pipe (I tested with a spare elbow I had)
Stock vs STI Perrin, you can see the vacuum line difference. The tape you see on it is me fixing a rip from previous owner.
Slip the new inlet in, not that difficult at all
Stock sensor bracket will no longer fit, remove all of the sensors from it and put it in your left over Legacy parts bin.
I had a hard time trying to attach the BPV hose back, turns out the fitting is bigger then stock so it requires some elbow grease to get it in. I found it easier to remove the inlet and insert the pipe into the BPV hose then insert it into the inlet.
Continued to post 2