Riveting the patent plate on firewall

[wrndln]

Does anyone have a good method to install a new patent plate on the firewall of a 28/29 with split rivets. I know it will take two people, one to press on the rivet head from the outside and one to installed it on the inside. The problem is getting to the split ends inside between the gas tank and the inside of the firewall. I am wonder what kind of tool would work best to bend the split ends over - just a regular screwdriver?
Rusty Nelson