I did mine some years ago, and borrowed a decent rivet tool. It cost me a fortune in the long term. I'd become fed up with the bike shop that supplied me with the chain that failed, and refused to go back to them to have the new one fitted as they did bugger all about chasing the supplier of the original despite the fact that it was still under the miles and years for the warranty (in hindsight, it was most likely a lack of adjustment that did it as in those days my paddock stand lived elsewhere and it had been ages since I'd done it). Anyway, with a decent tool it was dead easy to peen the soft rivets over. That act of kindness saw the bloke who lent me the tool become my regular spannerman until he retired at the beginning of this year due to poor health. Reckon I probably spent five grand on servicing and other work over the years due to the silly miles I racked up!
See if you can borrow a decent one, it's not something you want to use a cheap tool on and end up with a naff join. When mine broke, it sliced the chainguard into three very clean pieces, and smashed a fist sized hole in my carbon can!

I'm just glad it didn't hit a casing or my leg!