It really does not do much aside from maybe get the TB to run slightly cooler on start up which really doesnt mean much anyway - Ive tested this mod on other cars and it really does not do anything to make more power that you can feel.
What you do is remove the 2 coolant hoses that are routed into the throttle body and use a couple pipe between the 2 to attach them togther and it allows the coolant to bi-pass the TB.
Suposdly what this is going to do is keep the TB from heating up and allow for a cooler intake charge at the TB.....BUT take a look at where your TB is ....typically once the incomeing air charge hit the TB and gets into the runners on the intake manifold it is instaly warmed up from heat radiation off the engine itself.
Any sort of actual gains are so slight some dyno's wont even show a difference in HP.
If you really want a cooler intake charge look to a quality Nitrous kit or water/methanol injection