Use a small amount of the appropriate cement on a pipe cleaner to clean the sound bore along the entire length (thin cement for acrylic earpieces, vinyl cement for vinyl earpieces).
From the canal tip, insert a tube puller into the earpiece (monofilament for acrylic earpieces, wire for soft earpiece materials). Place the quilled end of the tube through the loop of the tube puller and pull through the earpiece (Figure 1).
When the tube is all the way through, adjust the tube by hand until you have it at the proper angle (Figure 2).
Pull the tubing away from one side of the sound bore and apply a small amount of cement. Capillary action will cause the cement to flow around the entire tube (Figure 3).
When the glue is dry, cut the tube flush with the end of the canal. You are now ready to refit the instrument (Figure 4).