Here’s an illustrated guide for accessing and replacing internal memory on a Gateway 7540 laptop.

Let me say something before starting…It’s not my fault if you break something while doing this!
This should only be attempted if you are familiar with electronics/computers and feel comfortable taking your laptop apart.
This may invalidate whatever warranty you have on your computer so be careful.
So in other words proceed at your own risk.

One of the memory modules is located under the keyboard and can be accessed only if you remove the keyboard.
Unfortunately, even after the keyboard is removed you’ll get only limited access to the internal memory slot. You’ll have to be creative when you are removing and replacing the memory modules installed into the internal slot.
Here’s a link for people who own a different Gateway laptop. Replacing memory, hard drive, keyboard on Gateway laptops