So, I have a 2011 iMac with a video card that's pretty well toast. When booting, it shows pink, vertical lines in the picture and then reboots repeatedly. I've mostly replaced it with a smaller MacBook, but I'd like to see what I might be able to get for it. I'm sure someone more enterprising than myself can replace the video card (which I think is possible in that model), but before I list it I'd like to make sure that the hard drive is wiped first. Is there any way to do that?