Hello, I have a MacBook Pro early 2011. I am planning to reinstall the OS at some time, maybe before or after the launch of Mountain Lion, because the current system is running slow. Now I have the disc came with my Mac, which is Snow Leopard. Is it true that I can reinstall the system only by installing the SL first and then download Lion from Mac App Store and then Mountain Lion (if available)? I know there're flash drive options but that costs too much. Also, if I replace my disc drive with an SSD, can I copy the content of the Snow Leopard disc to a flash drive and then install from there? Thank you so much!