There are 3 pipes. One incoming air at the front. The others are at the back, going to the exhausts.
Remove back two, and stick a plastic (so I'm told, so it's what I used) into the rubber pipe head first so that the pointy end of the tee is sticking a little bit out from the pipe. It shouldn't dissapear completely.
With the head of the tee blocking the pipes to the exhaust, re-attach them as they came off. Bolt back together and you're done.
PAIR is in one piece, but the feed pipes to exhaust are blocked so no air gets through.
I think I took some decent photos. I'll dig em up for you. All you'll need is a 2 plastic golf tees, a socket set (or wrench would do) to remove the PAIR valve casing and support bolts. and I used a flat head screw driver to help jimmy the hoses loose.