Dirty,
Hate to say it but why is that a question for this forum??? There are a few different thicknesses of pvc, take a tape measure measure across, find a drill bit and drill. If there is a little space I'm sure silicone chalking will work fine.
Sorry to be a bitch but I have seen the old timers here ride people hard for "questions" that could be more easily answered elsewhere. This is the first one I have seen where I would be agreeing with the old timers.
We can all help but we can't help you to help yourself.