There is no EASY way. If it were easy, the certification would be meaningless. If everyone could get certified without having to really work at it, then an employer would go "big deal, my 5yr old niece has one too".
Passing the test requires you to work at it. I prepared for about six months, and that was after I had been working and coding java for over a year. My prep time may vastly exceed others, but everyone works at their own pace.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors