How to upgrade from Mac Core 2 Duo Osx 10.6 10.7 10.8 to El Capitan: 1. Go to Apple Mac Osx El Capitan webpage then look for Number 4 and clown on Download. See Picture 1. for the exact link to download. 2. Once download is finished double click to let it run. When it is done click "ok" then restart Your Mac. 3. Go to Finder > Applications look for Upgrade El Capitan logo and then double click on it. 4. Let it run for about 40 minutes and then Your Mac will be upgraded to El Capitan :)