Great guide.
Do Apple do these kinds of upgrades in-store? I wouldn't mind a bigger HDD but don't want to go the external route and doing the upgrade myself gives me a sense of panic!!
Thanks... most definitely skip trying it yourself if you are not comfortable with the idea. Better to pay someone who is and guarantees the work than risk a mistake and bricking an expensive computer!
I'm not sure if this procedure would be offered at an Apple store honestly. I would imagine there are authorized dealers out there that might do it, but I'm doubting the Genius crew would offer this kind of upgrade in the store. On the iMac, any invasive type of repairs are usually just sent off to Apple, that has been my experience. Worth a call to see I would think....
Best of luck!