Here is a view of the bottom of the laptop with the base off.

The battery is on a cable and is easily removed at this point.

The hard drive is also on a cable but there are 2 screws holding it into position.

Unfortunately there is only one slot for memory, where currently resides a 4GB module.

I have not found documentation from Gateway indicating that it supports 8GB. But it is using the Intel HM65 which does support 8GB of RAM per channel in junction with the i5 CPU.

The second picture is of the base after it has been removed from the rest of the system.