I just put an electric start in my viper. to remove one I think you would remove the starter, battery, battery box and wiring harness on top of the battery. When you unplug the electric start harness reconnect the main harness back together. The electric start harness kind of "t's" into the main harness above the right footbox. The connectors are all keyed different so it should be obvious how to reconnect. you will need to wrap tape around one small (three pin?) connector so it won't short on anything...
If you want to test this theory before removing all of the hardware it should be easy enough to do the wiring first and try to start it up. you will have to loosen the plastic shroud to get to the harness connectors.
let me know if you have questions, I can try to help.