Very simple but time consuming to do.
All you need is your handy copy of memtest
, a notepad and an empty evening.
Put the RAM Voltage to it's maximum specified and the timings at it's specified.
Starting at the top of the list, drop the timings one setting at a time.
Also, only one field at a time!
After each change, run a pass of memtest for at least 10 or 15 min.
If there are no errors, drop the same setting one more notch and retest.
Make sure an keep track of stable/not stable as it is just as likely not to post as fail memtest when you push it to hard.
If/when it will not post, reset the BIOS and restart.
After you think everything is stable, test overnight with memtest to be sure.