Honda HP500H Manuel De L'utilisateur page 15

Carrier bed release lever
Pull the release lever to unlock the carrier bed when you wish to tilt the
bed for dumping a load. With the carrier bed unlocked, tilt it by lifting
the handlebar. To lock the carrier bed again, push down firmly on the
handlebar.
Before operating the power carrier check that the carrier bed is locked.
If the carrier bed is not locked, it may tilt while going downhill and
accidentally dump the load, which may cause personal injury and
property or equipment damage.
12
UNLOCK
LIFT
UNLOCK
CARRIER BED
RELEASE LEVER
LOCK
DOWN