You could make the body in two parts. One back piece that have is more or less solid. (Except for maybe a control cavity) and a front piece that you cut the neck pocket and pickup holes in first, before gluing the two pieces together. It's not elegant, but could work The biggest drawback with this is that the depth of the pockets is dictated by the thickness of the pieces you are using, which could cause problems.
Option to is to do as dcalde78 says, use chisels. That's how they did it in the olden days.
It does require lots patience, though. It's also advisable to get some good chisels, not cheap ones that go dull after 5 minutes.
Your last option is to get a router, which is probably your best option. Just read up on how to use one first. Routers are very nice tools if used correctly, but dangerous if you don't know what you are doing.