How to remove android from emmc

How can I remove android from my emmc flash as it was empty from factory? my board is bpi-m64

I want to do the same thing as im repurposing my BPI, could someone please answer

Hi, you have to run another system eg Armbian or Ubuntu Mate from SD card and then program GEPARTED - remove partitions on emmc flash and format.

But how do you boot to the SD Card when the Banana Pi boots straight to eMMC and does not look at the SD Card