Rivets are not difficult but need care. If you have stainless rod/rivets throw them away, they are too hard for wood but OK for synthetics like Tufnol.
How to fix rivets
1. Make sure the handle slabs are flat and the same thickness all round. Sand them on a piece of sand paper placed on a flat surface. Take one slab, put a few small drops of superglue on the tang and position the handle slab on it and let it dry form a few minutes.
2. Drill all the holes as squarely as you can, a drill press is very useful for this using the holes in the tang as a guide.
3. Knock off the handle slab with a sharp rap and repeat with the drilling second slab.
4. Take both slabs and join them together with the rivets. Shape the front of the handle slabs and make sure they are nice and smooth as you can't do much with that bit when they are glued to the blade.
5. After shaping, put plenty of glue on the handle slabs and tang, use 24 hour epoxy. Insert the rivets into one slab, use them as a guide to place them on the tang, put the other slab on the other side and tap the rivets through so they go through both slabs and the tang. Clamp firmly until set.
6. Once the glue is set, knock the rivets out with a nail or punch. Use files and course sandpaper to shape the handle but not too smooth.
7. If you have thrown away the stainless rivets and got brass rod instead, put the
rod in the holes, they may need to be drilled out and cut the brass rod 2mm proud of the handle on both sides. Make sure both ends are square.
8. Use a blow torch to heat the brass rod to red heat and allow to cool slowly.
9. Counter sink the rivet holes and lanyard hole slighty about 0.5 mm deep.
10. Here comes the tricky bit. Put the annealed brass rod into the holes with 2mm proud on both sides. Place the brass onto a hard firm surface such as a hammer head held in a vice and hit the brass rod squarely with another hammer.
Hit it a few more times to mushroom the head of the rod, turn over and do the same on the other side. If you are using a ball pein hammer, the best type for this, once the rod is spread, use the ball end to shape the head of the rivet into a dome and filling in the countersink. Be careful not to split the wood or put too many dents in it.
11. Once the riveting is done, use files to file it flush and use sand paper with a firm backing like a rubber to sand the rivet and not to undercut the wood around the rivet.
12. Once its nice and smooth, Bobs your uncle.
13. I recommend Corby Rivets if this is your first time, they screw on!