how do i reformat my mac hd disk?
Help!!!! My desktop mac is stuck in recovery mode. I ran the disk utility and it came back with "invalid node structure" "the volume macintosh hd could not be verified completely". I clicked repair disk but was unsuccessful. It said to reformat the disk. So how do I do that? And how do I get what my passport/external drive has been backing up all this time now back on my computer? Is this even realistic for someone with slightly better than average knowledge of computers to do?
iMac, Mac OS X (10.7)