20 Steps to Muscle Contraction and Relaxation

Help me put these in order for the 20 events of muscle contraction and relaxtion

I know number 1 is

Nerve impulse:

1. Nerve impulse
2. Cross bridge formation
3. NA+ channels of muscle open
4. Actin slides over myosin
5. Active Transport
6. Muscle Action potential begins.
7. Actin potential reaches the neuromuscular junction (believe this is 2nd)
8. Power stroke
9. CA+2 binds to troponin
10. ACH binds to receptors on muscles
11. Neurotransmitter released
12. CA+2 channels open
13. ATP rebinds to myosin head
14. NA+ pumped out of cell
15. ATP is hydrolyzed
16. muscle releases
17. Titan pulls e-discs back apart
18. actin shape changes opening binding sites
19. actin potential spread downs sarcolemma
20. crossbridges detach.

Thanks