If you have the Kaplan lesson book, there's a syllabus inside that you can kinda follow if you need some discipline. Make a schedule for yourself that's reasonable! Like, mine for today looks like:
"Natural Science Integration B" (which is a 90 minute test)
"Review Final" (which is review the answers to the Kaplan final, a full-length OAT exam, so I think reviewing it will take about 3 hours)
"Review Physics Subject Tests 1 & 2" (since I didn't review the explanations after I took them)
"Review ochem flashcards" (I paid for them, might as well use them, they're a good condensation of the notes anyways)
"Lesson book on ochem" (reviewing the notes in my lesson book from the Kaplan course)
I check off each item as I do it. I planned out every single day before the actual OAT (mine is next Wednesday, I finished the Kaplan course in late May and took 2 weeks off to study for finals, and then resumed OAT studying), but of course you can leave room for changes...sometimes you might realize that it'd be better for you to do a certain subject test on another day other than the day you originally set for it.
But yeah...get the syllabus, for example it tells you to read like Chapter 1-4 and do the online workshops (if you're not taking the class you won't have the workshops, but that's ok, the workshops have names, such as "Spectroscopy", so you can kinda create your own workshop based off the name! Haha), and do certain subject tests.
Then create your own schedule based off the syllabus or something similar, and follow it!
After I take the OAT on Wednesday, I'll post some more detailed advice and maybe provide scans of my calendar/schedule in case anyone finds it helpful. =)
You need to know some constants such as the two values for R (0.08 and 8), but they give you the following constants:
g = 10 m/s^2
c = 3.0 x 10^8 m/s
Qe = 1.6 x 10^-19 C