Hi there I got an old 2009 MBP 17'' that I'd like to wipe clean/ format and install Mavericks on. However there's no option to format drive and install fresh when upgrading to Mavericks via App store. How can I do it without a Mavericks USB stick? I do have a new 2nd MBP and FireWire cable so I could start the old MBP in "T"-mode but not sure how to install it from there. Any ideas?