To upgrade to Screenly 2, you need to either purchase a new unit from one of our distributors, or you could re-flash the SD card with the new disk image.
Please do note that you need a Raspberry Pi 3 Model B to run Screenly 2.
SD cards do unfortunately have a limited lifetime. As such, we strongly recommend that you get a brand new SD card before you upgrade. It's a small price to pay for to mitigate potential issues in the future.
If you're re-using an old SD-card, we strongly recommend that you first do an "Overwrite Format" with SD Formatter prior to flashing out the updated disk image using our regular instructions.
There is no way to upgrade to Screenly 2 without re-flashing.