you can just put a new image on the 64b card,
and then you need to extend the partition used for the patches.
this is pretty easy, as the patches are on a separate partition (mounted as /sdcard) to the main OS (aka rootfs)
I’ll update my resizeSDcard patch in next few weeks,
but you can do it manually as described here:
note: the device partitions have changed between the organelle-1 and organelle-m, so you will need to change these when following the process - this is why the resizeSDCard won’t work, and would make you organelle-m unbootable (except ive made it so it won’t run on the M 
) - this is what i need to update in the patch.
its trivial change - but the whole change, test, upload - ends up a taking a little more time that I have available at the moment.