basically involves replacing worn or broken parts with workable ones such as syncros,rings,hubs etc... anyway there is a writeup on how to rebuild one on VFAQ and i just had mine rebuilt by john sheppard and had him put in a GVR4 1st gear and i love it and he is recommened by alot of people. his site is http://www.shepracing.com hope that helps
1997 Mitsubishi Eclipse GSX: K&N Filter, John Sheppard built transmission with GVR4 1st gear, autometer boost gauge, "free mods", Greddy type-s BOV, broken shifter