downgrading ros from 7.17.beta2 to earlier versions

ok so as per my other post i have been playing with ros combinations
i have come across a issue that i can do
can anyone show me or like me a good video on how to downgrade ros from 7.17 please???
if im on say 7.16 i can open up winbox
drag drop over the 7.14.3 ros to the files folder
then drag and drop the wave2 drivers for my AX
then go to system/packages and hit downgrade and it reboots and the 7.14.3 installs and boots up fine

now do say situation on 7.17beta2 it dont work am i missing something here or doing something wrong?
or is it a thing with the new 7.17beta2 that you cant do that?? with the partion thing they said in it?? not sure
i have to go to system/packages and install the 7.16 stable then i can do the avove as per what i was doing before

any help muchly apreciated
cheers pete

You have to run system/device-mode/update downgrade=yes and press reset button or cut power.

ah thought it was that Thank you for the command i will keep that in my command book cheers pete

There is no such option in 7.17

http://forum.mikrotik.com/t/complaints-from-v7-17rc-testing/180325/1