Original post by: Dan ,
Follow this guide: [guide|899|iMac Intel 17" CPU Fan Replacement]. Don't let the title fool you! We are using it as it's has a good image of the PRAM battery. OK, follow the guide down to Step 13 pulling off the display. Jump to Step 18 but note the silver disk just under the persons hand, that's the PRAM battery. Carefully lifting the edge and pushing from the clip side you should have it pop out. Follow the Reverse order to put things back together.