How do you upgrade the RAM in the MacBook Pro? How much RAM of what type does it support?

Page 83 of the original MacBook Pro User's Guide notes that "Apple recommends that you have an Apple-certified technician install memory. Consult the service and support information that came with your computer for instructions on how to contact Apple for service. If you attempt to install memory and damage your equipment, such damage is not covered by the limited warranty on your computer."

Although EveryMac.com does not advise self-installation contrary to Apple's recommendation, the manual goes on to state that the MacBook Pro "Core Duo":

Has two memory slots that you access by removing the memory door in the battery bay. Your MacBook Pro comes with a minimum of 512 megabytes (MB) of 667 MHz Double Data Rate (DDR2) Synchronous Dynamic Random-Access Memory (SDRAM) installed.

Both memory slots can accept an SDRAM module that meets the following specifications:

• Double Data Rate Small Outline Dual Inline Memory Module (DDR SO-DIMM) format
• 1.25 inch or smaller
• 512 MB or 1 gigabyte (GB)
• 200-pin
• PC2-5300 DDR2 667 MHz Type RAM

The MacBook Pro "Core 2 Duo" models use the same type of memory, but support up to 3 GB with "a 2 GB SO-DIMM in one slot and a 1 GB SO-DIMM in the other." Apple notes that "you can use RAM module sizes of 1 GB or 2GB in the top or bottom slots." The MacBook Pro Core 2 Duo "Mid-2007/Santa Rosa" models introduced June 5, 2007, and the current "Early 2008/Penryn" models also use the same type of memory, but support up to 4 GB with two 2 GB SO-DIMM modules.

The User's Guide and Apple support site have installation instructions complete with drawings, which absolutely should be read in their entirety before one installs memory, but in a nutshell, the quick instructions are:

1. Shut down the MacBook Pro, unplug it, and disconnect any cords or cables.

2. Slide the battery latches up and remove the battery.

3. Unscrew the memory door and remove it from the battery bay.

4. Discharge static electricity by touching a metal surface [or better yet, use a grounding wrist strap].

5. Spread the tabs apart and slide out the existing memory modules.

6. Slide in the new memory modules, spread the tabs apart, and push the memory modules down until they lock into place.

7. Screw the memory door back into place and re-install the battery.

For alternate installation instructions, you also may wish to refer to the series of upgrade guides for different MacBook Pro models from the always excellent iFixit, which cover RAM installation along with other internal upgrades.