How do you study for the Lsats without buying their classes?

Kaplin or Prinston review. I talked to them and they said the only way you can get their book is if you sign up for their classes. Which is how they get you. I'm trying to get theirs classroom books WITHOUT class. I don't need an instructor I really really don't. Also which is better kaplin or Princeton review. Also do you need good grammer and written abilities to do good on the test> Cause I don't have that. I'm a electrical engineer major. Any advice you can tack onto that or pointers or anything would be great too. Go ahead and ramble about it.