i found either bending the tips on a set of needle nose plyers work's good, (needs heat to do this aka torch,) or using a set of 90* snap ring plyers works good too,
make sure you geta set that fit's the wholes fairly well but not so tight they pop out under pressure, and not a set so loose they pop out before you can eveen make a decent attempt..
but one word for yeah...
there-a-bitch!
~edit~ and yes the ebay ones work fine, some times you can get ahold of the vendor and have them send out just the ring for a few bucks, if you have problems finding it around town.