I know this one has been done before over and over again but please humour me 
DS2 (2.3) has suddenly started waking up between 5.30 and 6am and I need to do something about it!!
He is (and always has been) a fantastic sleeper and generally woken up around 6.30ish so I don't know what has changed 
He is wide awake aswell so have no chance of getting him to go back to sleep (have tried putting him in our bed and sending him back to his bed but neither has worked). He will happily go back to his bedroom (he is very obedient most of the time) but he shares with DS1 and will just wake him up and then we have 2 of them running round before 6am
as happened this morning.
Any thoughts??