Ten screws on the bottom case and you will have access to the ram and two more screws to free the hard dive.
Replace the ram with 8gb and hard drive with a 7200rpm, hybrid xt, or ssd... The whole thing will take less than 15 mins.
You will need a sata dock or enclosure to mount your old drive, use carbon copy cloner to clone the drive. You can clone before or after, doesn't matter since macs can boot from USB.
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