I've decided to replace the stock 160 GB in my iMac with a 500 GB Seagate. I've verified it's the correct type, etc. (serial ATA), but have a couple of questions concerning installation. I've done quite a bit of searching but keep getting different info depending on the post I happen to be reading. Don't the older G5 iMacs have fairly easy user replaceable parts? Am I correct in thinking it's the Intel and Rev. C iMacs that need "pro" installation?