You really don't - I learned this the hard way when I thought I could use my own intelligence to get by. After my first practice exam, I realized just how much my habits had screwed me and that I had a huge uphill battle ahead.
Step 1 is about memorizing as many details as you possibly can... any idiot can pull off a great score with enough time and effort.
I think you just need a solid basic science background to do well on Step 1. Being able to apply concepts you've learned is more important than memorization, but yes, there still is a great deal of memorization required.
You certainly wouldn't know it if you were to judge by some of the people schools accept...
If you're really just dumb as a post when it comes to making simple connections, I can see that costing you a few questions, especially on the BS department, but it's not something you can fix. Just memorize away, and try to get into the mindset the questions require. You'll be fine.