I had an Macbook Relic from late 2006 with manuscripts and important docs and it crashed (likely the hard drive) / Purchased what I thought was a direct replacement but got sent 10.7.5 Lion osx. Can I exchange hard drives between the two by physically pulling then while off and will the older hard drive function on the slightly newer computer (same white looking model everyone is familiar with) I am hoping it wasn't the hard drive to use in the newer unit. can I switch back and forth for diagnostics?