Remove the fan shroud and the front auxiliary engine protection panel. Press the drive belt tensioner by the hexagon (1) in the direction of the arrow and remove the air conditioning compressor drive belt (2).
Remove the bolts (1, Fig. 6.29) on the tensioner (3) of the drive belt from the rear side. Remove the tension roller with the lever (2) in the direction indicated by the arrow and remove the tensioner (3) of the drive belt.
The tensioner should be installed in the reverse order, while it is necessary to check the cleanliness of the drive belt, put on the drive belt and check the correct position of it on the pulleys, the groove on the drive belt tensioner housing should be directed downwards (arrow, Fig. 6.30).
Center the BMW X5 E53 drive belt tensioner, insert the bolts but do not tighten, install the tension roller with the lever and then tighten the bolts. Assemble the engine.