Hi, I have a macbook from about 2006-2007 running leopard, and I'm replacing my internal hard drive as I need more space. Previously I bought an external buffalo hard drive to put some of my files on, the hard drive is 465.65GB. Time machine has told me that to back up onto this all the files on there would need to be deleted, but I heard you can partition an external hard drive to keep your files and have a back up, how would I go about doing this? And would I be able to do it without erasing the files currently on my external hard drive? Thanks!