I use this activity as a Do-Re-Mi review for my older students. Before they try this activity alone in their group stations, we practice each pattern as a whole class. I also go over the steps they need to follow to teach their group members.
Basically, each group is given two Do, two Re, and two Mi boomwhackers. They are also given the instruction sheet and seven patterns (print out on cardstock and laminate). Each student gets to teach a pattern to their group. If a group finishes early, the students are instructed to switch patterns or try playing two patterns in a row.
Note: These patterns are in F major not C major like the Boomwhackers. The goal for my students here is that they are merely practicing reading Do-Re-Mi on the staff - not matching exact pitches.
You can find the Powerpoint and more instructions here: Do-Re-Mi Boomwhacker Activity