I can't believe there are 76 posts about how to remove a plastic screw that you don't need to reuse.

Drill the sucker out. It's plastic, for goodness sake, you don't even need power tools. A hand drill would work, or even just a drill bit held in your fingers. I keep a coffee grinder style hand drill and a brace and bit style handy just for places where I don't need high power and or don't want to go find an extension cord.

Or get a propane torch and melt the head off. Everyone here (except the OP) could do this job faster than it takes to type one post.