your gonna need a set of star allen keys halfords sell a set, not that expensive, i cant remember the size but its in the set, its one of the bigger ones thats included.
their is 4 to remove in total, easy job, might need 2 people coz they are pretty heavy and it helps to have someone hold it straight till all the bolts are out, also - cant remember but i think its the door side you need to unbolt from due to clearance
either way its a 10 min job per door