A Valve Spring Compressor apparatus and method for compressing cylinder valve springs for the removal and installation of the locks or keepers and also for replacement of valve stem seals or broken springs onto an internal combustion engine, whereas the cylinder head is mounted onto the motor or supported to a work bench. A compressor tool adjustably mounted on a support assembly temporarily secured over the Hydraulic Cylinder head has a pivoting hand lever and spring biased push rod which, when manually depressed, moves a compressing member at the bottom of the push rod downward to engage and depress the valve spring and its retainer to gain access and removal of the lock or keeper though openings in the Engine Tools.