This is exactly the problem I faced when I's prep for step1.
You have to do questions
start doing Kaplan qbank subject by subject for example
you finished 2nd review anatomy, start doing kaplan qbank only anatomy
then you finished 2nd review biochemistry, start doing kaplan qbank anatomy and biochemistry
so when u finish all books second time you'll see yourself doing everything in kaplan qbank.
don't worry about forgetting, most important is the questions
You have to do questions
start doing Kaplan qbank subject by subject for example
you finished 2nd review anatomy, start doing kaplan qbank only anatomy
then you finished 2nd review biochemistry, start doing kaplan qbank anatomy and biochemistry
so when u finish all books second time you'll see yourself doing everything in kaplan qbank.
don't worry about forgetting, most important is the questions