Open the vanes of the vertical blind with the wand. The vanes should be pointing perpendicular to the window or sliding door.
Grab the carrier body with a pair of needle-nose pliers. Grab the body on the flat portion and as close as possible to the carrier stem without touching the stem.
Hold the carrier body with the pliers and twist the stem left to right with your free hand. Pull down on the stem as you twist it until it comes out of the carrier body.
Take the stem to a blind dealer or home improvement center to match a new one. The carrier stems have a variety of different connecting ends and must be replaced with the same configuration.
Insert the end of the carrier stem into the hole in the carrier body. It takes some force to push the stem in until it clicks into place.