Ryan,
This topic has been discussed here often.
There is no real short cut, the only thing that works is elbow grease.
Acetone, and lacquer thinner and others work, but they soak into the balsa so fast they really don't have time to work, and after they evaporate they leave a residue that will make the new covering no want to stick.
The only real way is to use a heat gun to soften the glue a little, peal as much off as you can. Then go back and sand the remaining small pieces and glue residue off with light sand paper.
It takes some time, but it's faster than building a new plane.

Good luck