I'm doing this - well, mainly using Kaplan for the questions. I just do my normal review using other books (non-kaplan), then hit up the corresponding section on Kaplan, and do their problems. It's pretty intense, but if you just make it a part of your schedule it isn't too bad. It takes me about 4 hours per day to do content + Kaplan questions. It's definitely demanding, but very possible.
I think the key is to just accept it as part of your schedule and move on. The minute you start to think, "Man, this is a lot! But I'm going to step-up and do it!" you're already telling yourself that it's something you have to prove to yourself that you can do. Just accept the task, and do it! If I'm able to do it so far, I know you can!