51 23 131 Adjusting left or right striker on engine compartment lid

Adjusting striker is described in: 

Adjusting engine compartment lid. See ADJUSTING ENGINE COMPARTMENT LID or ADJUSTING ENGINE COMPARTMENT LID (VEHICLES WITH ACTIVE PEDESTRIAN PROTECTION) .

Unclip anti-twist lock (1).

Unscrew retaining hook (2).

Installation note: 

Adjusting engine compartment lid. See ADJUSTING ENGINE COMPARTMENT LID or ADJUSTING ENGINE COMPARTMENT LID (VEHICLES WITH ACTIVE PEDESTRIAN PROTECTION) .

Fig 1: Identifying Anti-Twist Lock And Retaining Hook

Courtesy of BMW OF NORTH AMERICA, INC.