1. Remove the b/f# key (Fig A). Taking care not to damage the key pad. 2. Slide the end of the collar (5) under the keywork between the finger holes and attach the loop to the lower pillar (Fig A) of the b/f# key. This will prewent the collar from sliding under the ring keys. Replace the key. 3. If you have Bb clarinet with an extra Eb-lever, remove the parts on the left side as shown (Fig B). Attach the collar to the lower pillar.