Depends on the kit, but you will need to remove the airbox, and connecting pipe to the turbo inlet hose(connects just under the edge of the engine cover).
From there, attach the new hose, and brackets and away you go! Shouldn't be too hard.
Thats half the fun, trying to figure out how to do it! haha.. Be a grease monkey and get stuck into it i think there is a DIY on removing a resonator here or on legacyGT, follow that and figure out the rest.