How do I clear an aircraft to exit a hold?
This depends on what exactly you want the aircraft to do:

Immediately depart the hold and fly directly to another fix:


  N1234 cleared to 'clearance limit' via direct 'fix' and then as previously filed.


Immediately depart the hold and fly an assigned heading:


  N1234 Cleared to 'clearance limit' via radar vectors. Fly heading 'heading'.


Proceed to another fix after passing the holding point inbound:


  N1234 After 'holding fix', cleared to 'clearance limit' via direct 'fix' and then as previously filed.


Fly the published approach after passing the holding point inbound:


  N1234 Maintain 'altitude' until 'holding fix', cleared 'approach name'.


Altitude

Lastly, add the altitude to any of the above clearances if it is different than the current altitude by adding a climb/descend and maintain  'altitude' clearance.