I just purchased a 2015 MBP non retina, an upgrade from my mid 2009 MBP. The old one comes has an SSD with El Capitan installed, which I'd like to use in the new one, but I got the crossed out circle after I installed and booted it up. Can I just reinstall El Capitan with my old SSD in the new MBP, and keep all the data and it will boot up fine? or does something more complicated need to happen? Thanks!