Couple of other recommendations, once you have the cap off, use a black fine point magic marker to mark the seated position. When you remove the retainer bolt and pull the distb out put two fingers UNDER the dist and your thumb over the rotor then lift straight out as said, use a second color, red, to then mark the removed position. You will only be able to do one side as your palm will be blocking the other. That way with two colors you won't get them confused.
Put some vasoline or assembly lube on the O rings before you slide the new one back in. Also clean the area around the dist before you pull the old one out, don't want to dropping any crap in there...
