Deleting / destroying a Raid array

Get infos about the raid:

sudo mdadm --detail /dev/md0
 (or md1 or ...) 

stop the raid array:

sudo mdadm --stop /dev/md0 

send a “zero-superbloc” to each partition that has been member of the raid

sudo mdadm --zero-superblock /dev/sdXX
sudo mdadm --zero-superblock /dev/sdYY
etc...