Not enough time unless you are cycling! Its 12 mins on the H&C line ( get off at the back not the front of the train. The front is nearest the Circle Line entrance but the Circle Line is no longer a Circle but is broken and requires a change at Edgware Rd). Its about 6 mins between trains so you need to allow 20 mins Tube platform to Tube platform plus time to get from train to platform and back.