As far as I can tell from general poking around the way bitcoin works is set in the protocol that the nodes talk to each other. Simply puy to change the way bitcoin works you'd need to fundamentally change the protocol bitcoin uses to talk to other nodes. When you change the protocol it uses it can no longer talk to other normal nodes. There is one other way to change the amount of coins in circulation however, the dev(s) have a key that lets them print money. odds are good the dev(s) will make a shit ton of coins from this and not delete the key. unless someone somehow gets the key then you can't add new currency technologically.