There are 3 options maybe more hopefully someone with more experience can chime in. The first one I haven't tried. Because you downloaded the emmc one and it's now booting from sdcard I think when you first power up after the first 10 seconds of black screen you press ESC and it should start the installer.
Option 2 is to get a usb emmc adapter and flash to emmc using Etcher.
Option 3 is after you booted Manjaro from sdcard download the image again and dd it to your emmc, once completed power down then remove sdcard and power back up. In this thread look at post#7 and replace the debian image with your Manjaro image in the wording of the code.
https://forum.pine64.org/showthread.php?tid=8229
Hope this helps.
Option 2 is to get a usb emmc adapter and flash to emmc using Etcher.
Option 3 is after you booted Manjaro from sdcard download the image again and dd it to your emmc, once completed power down then remove sdcard and power back up. In this thread look at post#7 and replace the debian image with your Manjaro image in the wording of the code.
https://forum.pine64.org/showthread.php?tid=8229
Hope this helps.
