If one was willing to sacrifice a cheap uke to try this then a hole saw drill bit should do the job quickly. But how would you prevent the sawdust from falling into the uke?
Siv, bold move dude. I see the wandering bit. That's why I'd use a Dremel only. And the pattern I chose leaves a lot of material around the edges if I screw up I can still salvage it.
Do post any fixes you do to your uke. I'm not deterred. But, I sent a message to Pepe Romero Jr. We'll see if he returns my message.