Lower the forks so that they are just below the bed. Note that some sideloaders may have only a little free lift. In those cases, lower the forks until the overall height of the mast is not increased.
Retract the jacks, (if fitted), carefully check all around before moving off.
Disclaimer: The legislative information contained on this web site is my interpretation of the law based on many years in the health and safety business. A definitive interpretation can only be given by the courts. I will therefore not be held responsible for any accident/incident/prosecution arising as a consequence of anyone using any information obtained from this web site.