Here's how I did mine:
Disconnect each vacuum line at the manifold end. Push down gently on the black collar with a screwdriver and pull up on the plastic elbow and it'll come right out. Only disconnect them one at a time or you'll get a vacuum leak.
Find some tubing that fits snugly into the hole in the manifold and wedge it in there (no air leaks). Insert the little red tube from the can of Berrymans an inch or so into the other end of the tubing you inserted in the manifold and duct tape it in place (again, no air leaks).
Attach the can of Berrymans to the red tube, start the car and spray away. Try to use about 1/2 the can and don't spray too fast or the engine will stall. Repeat the procedure for the other manifold line.
They say it's a good to do this right before you do an oil change.
