Well it's going to be tricky with the manifold on the car. Mine just slap busted clean off the a manifold, as I said, so I glued the whole thing back on, which means it is glued back on with a fillet of JB Weld all around it. Mine busted off below the rectangular base of the two hose connections, where the base is mounted on the manifold. If you look in there, you'll see the two connections/spigots sticking out of the rectangular plastic base.

Since mine broke off there, it is reasonable to think that is a weak spot, so put the JB weld all around the base of the rectangular part where it lies on the manifold. Make sure you clean the crap out of it or else the JB Weld won't stick. I would blast it with brake kleen and then swab it good with q-tips saturated in brake kleen. You could also use lacquer thinner. This procedure will also etch the plastic and roughen it up a little which will aid the adhesion of the JB. You'll need to use a mirror to see the back edge of the rectangular base part up against the intake. Mash the JB weld in there good with your fingers. You can wear a latex or nitrile glove, mash the JB in there, then smooth it out and press it in there good with finger dampened in lacquer thinner. Spit also works for this.

That is what I would do. Since you can't access this very well I think you are going to have a tough time adequately getting the JB in there. But it's worth a try, it's cheap, and you got nothing to lose but your time. Let us know how it works out!