If you don't want to pull it then just reach under there. There's two right in the middle and one on the driver side of the intake. Make sure the car is cool, of course.
They are a b**** to get to. When I had my upper off to smooth and paint it, I installed it back on, had EVERYTHING hooked back up and realized I forgot the very bottom vacuum hose...needless to say after a few choice words, I took it all back off and put the hose on (a very nerve-racking thing when you are working with a freshly painted intake).
Take off the STB and pull off the upper. My hands are way too big to reach under there and that's what I had to do. It really isn't a big deal, the hardest part for me was lining it up to put back on.