How to extroot on Openwrt Huawei HG553

IMPORTANT:
I forgot to set the mount option in this video, don't forget that, here's my fstab configuration

config global
option anon_swap '0'
option anon_mount '0'
option auto_swap '1'
option auto_mount '1'
option delay_root '5'
option check_fs '0'

config mount
option target '/overlay'
option device '/dev/sda1'
option options 'rw,sync'
option fstype 'ext4'
option enabled '1'
option uuid 'f35dc6c4-480a-416d-9116-8c933c2dd0a7'
option is_rootfs '1'

Keyword:
How to extroot on Openwrt Huawei HG553
Cara extroot openwrt
Cara extroot openwrt huawei HG553