Cards are easy to study in 1 month, but in my opinion that will not help you - since card are easy to read and will help you study quick - but the bitter truth is will not help it to remember. There are some memoronics - I used few of those and I made mine for the rest.
The main point is you should be able to remember all card, I studied card at least 10 times, and believe me now about 70% card I can see if I close my eyes.
If you have bought combo - once you are ready call prontopass and let them ask question, and then you will know how much good is your preparation.
Too long answer....
Good Luck for Naplex....
Ashish