Upgrading the system memory is the cheapest and simplest improvement for any computer. In this post I will describe the process of installing new memory in a MacBook Pro. For $36 - $164 discount over Apple - I was able to extend the usefulness of my machine.
The first step is to buy RAM that is compatible with your system - 13" MacBook Pro 2011 in this case. Finding the correct memory is simple. Go to amazon.com and search for "macbook pro ram". Most of these products are completely compatible and the reviews will provide additional information. I chose the Corsair 8 GB DDR3 kit (CMSO8GX3M2A1333C9) based on my past purchases from Corsair.
A #00 phillips head screwdriver is needed to remove the bottom panel from the MacBook Pro. There are nine screws, three long and six short. Some of the screws are inserted at an angle. To avoid stripping these screws use the driver at the same angle as the screw.
Once the machine is exposed locate the memory currently installed. It should look similar to the new set. Each stick of memory is held in place with a retention clip. Pulling both sides of the clip away from the RAM will release it. Once free the RAM will rotate slightly to allow easier removal.
Repeat the same procedure for the second stick. Now it is time to insert the new memory. This process is the reverse of removing the memory; slide memory into slot, rotate downwards, ensure that the clip is properly attached to the new stick.
Now that the new memory is installed it is time to close the laptop and test out the upgrade.