First, line the snorkel up on the wing. You should of got a template, i did not have one so i did it by eye. Mark out where the hole is going to fit and open the door to make sure it wont catch on the snork, then remove the wing. I found it better this way, you may be able to leave it on, but id take it off.
Cut the hole in the wing and then mark out the bolt holes (Like i said i had no template, you should get one) drill the holes and fit the snork into place.
Once bolted into place hold it to the truck to find where your going to need to cut a hole to fit through.
Then remove the airbox and cut off the section that fits into the front of the wing. Then either weld a plate over or pot rivit it and seal it.
Now the only photo i did not take was the new hole on the air box.
You need to cut a hole and weld a new section on, i used 3" stainless steel thats used for exhaurts, you only need about 4". as too much and you will run out of room. Then get some flext pipe (Ebay) to fit through the wing and onto the new 3" pipe. so it looks like this.
I also put some rubber round the wing edges to stop it cutting into the flexy tube.
As its for a D22, you will have some bits that you wont need, so dont look for where they go, :lol You only need the main body and the scoop. (And the nuts and bolts.
I have not fitted the door mounting either as i did not get one.
This is the end result
DO NOT BE TEMPTED TO GO IN TO THE REAR OF THE AIR BOX AS IT WONT WORK. YOU WILL END UP BYPASSING THE AIRFILTER IT HAS TO GO INTO THE SIDE OF IT.
Hope this helps.