Hi, Upgrading to Mac OS Sierra may have bricked my MacBook Pro 2010 (running a SSD) and I'd appreciate some help resolving. I downloaded Sierra via the App Store in El Capitan and started running the installation wizard. All seemed fine - the MBP restarted itself and I was given a screen saying "insufficient disk space to install, click here to restart". So I did. The MBP restarted itself and since then has been stuck on the grey/white screen with the Apple logo and progress bar stuck around 75% - overnight. Here are the real problems - 1) I can't boot in safe mode by powering off, repowering up and hitting SHIFT (left or right) when I hear the chime. It just gets stuck on the progress bar. 2) Similarly I can't boot in recovery mode by doing the same and holding down CMD+R. Again gets stuck on progress bar. Any thoughts?? Thanks!!