A very important resource for working on challenging lessons is the human capacity for disobedience and cheating.
After all, when faced with a choice between Obeying the Command of the Teacher and preserving your own well-being, why would you ever choose to do what the teacher tells you to do?
So if the lesson says “leave your knee on the floor,” try a few repetitions where you let your knee come off the floor. If the lesson says “lift directly towards the ceiling,” try lifting to 45 degrees from the ceiling, then 30 degrees. then… And so on.
You can also vary the configuration. Do the instructions say to place one knee on the floor in front of the other? Try placing the knees one on top of the other. (This is in side-lying.)
The important thing when you’re cheating is that you know you’re cheating. Do it with awareness. So that eventually you can come back and do the lesson closer to the given instructions. (Cheating in itself doesn’t matter, but if you don’t know you’re cheating, you can’t correct yourself over the long haul.) A given challenging instruction probably makes its odd demand for a very good reason. But that’s no reason to hurt yourself to uncover the secret. You’ll get there soon enough.