Originally Posted by photolinger
I either sand my grommets down or apply a silicone lubricant on it. Dont judge me, it slides in like a charm
+1 I'd do both. Sand it down a bit then pick up a tube of lube that is made for o-rings (wont destroy the rubber grommet). In a pinch I've used hand lotion to slick it up and slide it in when its tight.