For the 6-1/2 mo rotation you repeat each disc 2x. For week 1 do discs 1-3, repeat in week 2. Week 3 do discs 4-6 and repeat in Week 4 etc. Take your recovery week after Week 8 and Week 16.
Cathe has mentioned that the system is really designed for 6 months but figured most people would get bored with too long of a rotation.
Also, I think I'd seen on suggestion of only repeating M1 & M2 2x but doing M3 just once.
HTH