Go for it I know how you feel! This is the way I did it. I covered the bonnet with 75mm wide masking tape to protect it marked the centre line and cut it in half with a 22 tooth hacksaw blade ( I don't trust my angle grinder for this). Refit the bonnet to make sure that it still lines up then took 2 more cuts to allow 8mm for the hinge pin. Cut the hinge to length making sure that the hinge sections are equally balanced and mark out for the rivets or in my case m4 dome head bolts and nuts on the bonnet sections. Drill the holes in the bonnet sections, I used a 4.1 carbide drill in a bench drill, then clamp the sections one at a time to the hinge and drill through. I put nuts and bolts in at about 4 hole intervals as I went to keep everything straight. Dismantle it, slightly countersink all holes and assemble. That's basically how I did it.