Make sure you buy the solderless redi-prongs. I usually just use a
fine tip pair of tweezers to hold the caps. Sometimes I will take
Radico, which is a green compound used by watchmakers, on the end of
a 3mm wood dowel sharpened with a flat spot to hold them in place. I
also use Radico for covering heat sensitive and dark stones to avoid
damage from the laser beam.