If you have extra people you can use two long pieces of timber (3m) to make a ramp up to the cargo door. Four people is ideal so you can have one on either end of the drum and two guys pushing it up the "ramp". It isn't the safest but it works if your in a fix. I carry these drums everyday almost and we have found putting them on a ute first is easiest.
Strapping them down once they are in the van is a whole other story.