The biceps consist of two heads, the short and the long head. The long head is the outer most head and is what will be the focus on this routine. If you cannot do chinups with a neutral grip ( palms face one another ) then use the assisted pullup/chinup machine or have someone assist you or use bands.
Standing dumbbell hammer curls ( both arms at the same time )- 10 reps
Neutral grip chinups- 6-8 reps
Rest 90 seconds and repeat 3-4 more times.