I have a few questions about a MacBook Pro I just bought. I'm a computer science major and I have been wanting to dip my toes into the Mac world to get familiar with the OS. I picked up a mid 2010 MacBook Pro for 175 on eBay. The computer has 8 gigs of ram and the standard 500 GB hard drive. The battery is is shot on the system so I have to run it off the power cord until I find a new battery. (Also i was playing music and after about 45 minutes it cut off, I dk if it was because the cord was lose or what) Biggest issue I have is the previous owner didn't have the original discs and he never logged out of the computer (he just deleted his files). I made an appointment with the Apple Store for tomorrow to see if they could wipe the system and reinstall the OS. The OS currently on it is Yosemite but I believe it shipped with Snow leopard. Just wanted to ask if there was anything I can do to wipe the drive and reinstall the OS without going to the Apple Store. Thanks for all the insight.