downgrade version from 5 to 4.16

hi
i want to downgrade my router from v5 to 4.16. :confused:
how can do it?
thks

You need to use the netinstall to downgrade

http://wiki.mikrotik.com/wiki/Manual:Netinstall

Is it the only officially supported way to downgrade, or is it at least the safest?

Because I used to downgrade through “/system packages downgrade”.

You should be able to downgrade with “/system package downgrade” as usual