Or use a very small bit all the way around the outline of your rout and chisel it.
One of the reasons I specifically like hand tools is because things happen slowly.... though I've been using them for 45 years, and I have some chisels & stuff inherited from my grandfather. I can usually have something
done by hand before I could have the power tool out, find all the right bits etc. - it doesn't sound like you have a workshop, or much experience with routers, huh?
Consider spending $100+ on a router than can ruin a $300 body in TWO SECONDS, or $20 on a couple of chisels that
can't. "Power tools save time" - how long do you have to work to make the $300 to replace the ruined body? Consider people's assessment of the early C.F. Martin guitars and Stradivarius violins, made with hand tools - quality of the work is not an issue for sure, just speed.