I have a rotary watch that needs a new battery, I have tried to take the back off, but the glass and strap comes off leaving the face and back intact and no accesas to the battery. Any ideas my friends in the ether !

Are you sure it needs a battery, Not manual or self winding?
Model or Photo?

Are you sure it needs a battery, Not manual or self winding?
Model or Photo?

It's actually my brother in laws watch and it has had a battery before, I will try and get a photo online soon, cheers Strat !