Hello everyone, I have ordered the rMBP and I have sold my previous 27" iMac to my father and now need to clear the computer in order to give it to him in the same state as when I brought it. I am switching because I need portability. I have just watched a few videos and they just inserted the install DVD and then went to Disk Utilities etc. The problem is, I cannot do this. When I click on install OS X after inserting the DVD, it states that I cannot due to the fact I have Lion on my machine. I am not worried about not having Lion because once he is on Snow Leopard, he will be upgrading to Mountain Lion anyway. If someone could go through it step by step that would be awesome, I have yet to find a video on Youtube explaining how to clean a mac to factory state with Lion, whereby the Disks are for Snow Leopard. Many thanks in advance, George.