tage, I was unable to PM this to you has you have PM turned off. Please do not just tag onto someone else thread with a completely different topic. Use the Post Thread button instead of New Reply 
At the moment, you can't. You can only boot from the microSD, or the onboard eMMC, and are restricted to the operating systems provided. The pinebook is still very new, and I have heard of people working on
other distributions.
At the time of writing, these are the possible pinebook OS install choices. This is a screenshot from the Pine64 Installer, which will let you download and write to your microSD card. Please note that the installs that say for eMMC will automatically copy from the SD card to the eMMC, overwriting whatever you currently have there, and most likely without any confirmation.
At the moment, you can't. You can only boot from the microSD, or the onboard eMMC, and are restricted to the operating systems provided. The pinebook is still very new, and I have heard of people working on
other distributions.
At the time of writing, these are the possible pinebook OS install choices. This is a screenshot from the Pine64 Installer, which will let you download and write to your microSD card. Please note that the installs that say for eMMC will automatically copy from the SD card to the eMMC, overwriting whatever you currently have there, and most likely without any confirmation.