This is the best tool I have found to complete the job. You need a helper to have a magnetic tool ready as you compress the valve. Autozone may only have the regular valve spring compressors which won't work. It must be like the following:
New Engine Overhead Valve Spring Remover/Installer OHV/OHC Compressor Tool Set | eBay
You also need a good compressor. I recommend you buy a leakdown kit and do it since you are doing 90% of the work required to perform a leakdown test and you'll get a good idea of engine health.