BMECP is not far from the Clarendon Centre. In fact, if you’re coming down to the Clarendon Centre from the train station, you will pass BMECP on your way.
BMECP is on the ground floor underneath the sports hypnosis centre
If you’re not sure, take a look at the street view to see what it looks like from the outside.
BMECP will not open until 8:30am. If you are in Brighton before then, proceed to the Clarendon Centre as there will be no access to BMECP before 8:30am.