This will show you how to change a valve stem seal on a 2001 Mazda Protege MP3 (FS-DE) engine without having to take off the cylinder head. Removing the valve cover, removing the upper and lower timing belt covers, removing the harmonic balancer, loosening the timing belt tensioner, slipping off the timing belt, installing the harmonic balancer back on (without belt) to be able to crank the engine, and removing the cam shafts are the steps to prepare for the process.