Must say I'm kinda glad to hear I'm not the only one stuck. For me it's week 3.

Like Blast said, even if this 6-week program is impossible it still has value. It is simple enough that it has re-started my languishing fitness routine, which is now branching out into other activities and exercises (like tabata squats and running).

Glad to have found mention of it here as well as Tom_L's link to an alternative program and the pull-up programs/DIY bar.