I am replacing the 5400rpm drive in my 2009 macbook pro with a 480gb ssd. That part is easy. I want to do a clean install of yosemite on the ssd then install all the software fresh. I don't want to install a clone on the ssd but I have a current clone on an external usb drive. Now with the app store and yosemite being free, etc., I am unsure how to go about a clean install if the computer only has a bare drive with no operating system on it, the os is an internet download, and I have no installation disk for yosemite. There must be some fairly simple way to do this. Thanks for any advice.