After reading many of the ssd related topics I came to the conclusion that the easiest procedure is to just REPLACE the original HDD with an SSD. It sounds as straightforward as removing the glass, unscrewing and lifting the screen after unplugging 1 to 3 connectors and replacing the HDD with the SSD. No additional cables needed, no removing the logic board. Just easy stuff. Some people are reporting fan issues while others report no issues at all. Seems these issues are SSD brand related. Using vertex 2 and vertex 3 SSDs seem to lead to no problems at all. Using intel 510 SSDs seem to lead to fan issues. I don't know about passing the apple hardware test. I don't know about other SSD and HDD models. Everyone who has REPLACED their HDD please post your experience here so we can make a database with what works and what doesn't. Doesn't hurt if this topic becomes sticky too..