I ran onto these instructions for replacing Lippert six-leaf hinges this morning. It recommends using self-drilling screws so it appears screws should work for yours.
Lippert RV Entry Door Hinge Replacement Pub T!-260 (pdf)
You probably won't want to grind off the old rivet heads as you might mar the surrounding area with the grinder. The rivets are aluminum and you should be able to easily drill them out. Use a center-punch to make a divot for the drill bit (so it doesn't just wander off the rivet head). Ideally the drill bit would be the same size as the rivet pin and the rivet heads will come off and you can push the pin on through. (If in doubt, start small and increase bit size until the head comes off).
Searches for Lippert hinge repair in RV forums show some recommendations to drill out the rivets and then replace those rivets with pop-rivets (aka blind rivets) after the repair/replacement. You'd have to choose a pop-rivet material and rivet length to get it right.
It appears replacement hinges don't have holes in some of the leaves. Installation requires drilling your own holes to match the old hinge. Also- note that the instructions say to replace one hinge at a time.
You might also want to call FWC Service (and/or Lippert) and discuss before proceeding. They may have suggestions on what screws to use and you can discuss where to get the exact replacement hinge you need. You might also look on the hinge for any part numbers to search.
As I write this, I'm reminded of a repair I did on my door several years ago. I don't think it applies to your situation as the binding is probably internal to one or more hinge leaves. But it may be useful to someone searching for hinge-repair/replacement info.
This video has the idea.... put a washer in the hinge.
How I fixed my saggy RV door
It didn't quite work the way this guy shows as the stainless lock washers I found were all too thick. But I did find thinner regular stainless washers. I cut out a slot just big enough for a force fit on the pin. This fixed the problem of my screen door sagging enough to touch the threshold.
PS- As I went to post this I noticed you had posted the Open Roads Forum one. I decided to post anyway.
PPS - If you do replace the hinge and get part number info, please post that info. Future searchers will thank you!
