Go to an auto parts store and pick up a thermometer for A/C testing. The range is perfect. Stab it into the rear quarter to monitor the temp. You want 38 deg. If it is warmer, shorten your aging time. Colder and it isn't doing what you need, but still doing what you don't need. Age it on the bone at least long enough to relieve rigor mortis (3 days?). Use the guide posted above by UWyo.
