I missed Friday and Saturday so made an extra effort this morning and will do it again tonight.
I find that if you know the levels well, you can substitute a hated exercise with a preferred one from another level. I do jumping jacks instead of squat thrusts sometimes. Also on Ripped in 30, level one has 30 seconds of holding the plank pose, so sometimes I do that instead of plank jacks.
I figure that something is better than nothing and it's just important to keep moving and do something.