There are two styles of luff protectors and they all come/came from the factory installed with rivets. The old style has four rivets and the new style has five.
If you have the old style protector, all you need to do is order this kit from Murrays...
You carefully drill out the existing rivets and install this kit using a standard screwdriver (use loctite on the screws).
If you have the new (last 10 years or so) style luff protector with five rivets, then you have two options. You can order the replacement luff protector from Hobie which is intended to be installed with rivets using a special tool (however it may be possible to modify it to use machine screws and nuts). Or you can replace it with the old style luff protector, but you will have to add two small holes to the sail because two of the screw holes won't line up with the existing holes. Use a soldering iron or a nail heated with a torch to melt the holes. This is what I did on one of my sails, although I had a sail shop reinforce the luff with some dacron before adding the holes.