Locate the orifice that connects the base of the grill and the hose to one another.

An orifice is a valve commonly found on gas powered home products. This allows the gas to pass through from the source (i.e the propane tank) and burn properly.

Conncected to the orifice should be a nut. Use the crescent wrench to turn the nut counter clockwise and remove the hose from the base.