OT, installing a new HHD in an iMac. Fun....

[bobswire]

First off, using Time Machine to do backup in your new HDD is pita after installing it then finding out it won't allow you to upload your OS. I found away around it but it took awhile. Why wasn't I warned?
Secondly make sure you have the Original OS disk that came with your iMac computer if it's older than 7-8 years.
Thirdly,plan to waste a whole day reinstalling "stuff' you want to save. Most of the files on my old HDD was like a hoarder whose house is fulled with junk he or she will never ever use or need.
Finally,was it worth it? You you Betcha! Like getting a Joe Bell repaint and modern components on your Serotta Colorado.

http://i59.tinypic.com/2s9yh6d.jpg

[ceolwulf]

I need to do this on my Mac Mini soon. I have an SSD waiting to go in it. It's just that combination of free time and nothing else I'd rather do that seems very scarce.

[carpediemracing]

I used Carbon Copy. Makes a mirror image of the drive. Then the original drive becomes the backup.

http://download.cnet.com/Carbon-Copy-Cloner/3000-2242_4-10169677.html

[gavingould]

Uh, they don't warn you because the HDD in an iMac is not meant to be a user-serviceable part... They don't want you to open that thing up! Time Machine is fine for file restores but I wouldn't rely on it for OS. I've owned a few iMacs from the first gen of Intel onward, always sold them and upgraded to a newer one every ~3yrs.
If you want really reliable backups or a full bootable image, Carbon Copy Cloner is an excellent choice.

[Henrythewound]

It may be easier to get at on an older iMac like the OP has. I have a 2010 (I think) and a HD recall allowed me to take it into the Apple store for a replacement. I believe it involved heating up the edges to remove the front glass panel to get at the innards, not something I would attempt by myself for sure

[mktng]

i've been postponing this task for a while. after reading the iFixit tutorial.
*sigh*

cant wait to slap an SSD into the good ol iMac.