Right, to start off with I can't see any extra hardpoints on the Dromedary, this is what I see when I open the model in hardCMP:
So, go to Program Files/Microsoft Games/Freelancer/DATA/SHIPS/Border_worlds/BW_Freighter and opn up bw_freighter.cmp with HardCMP.
Now, to add a hardpoint, click "new" and then select HpWeapon.
Make sure it's attached to the "Root" section.
And then point at the place you want it with your mouse, hold down ctrl and click.
Now, File>SAVE AS. DO NOT SAVE. HardCMP doesn't save, so you lose all your work. Weird bug. Anyway, Save as the original file name and overwrite it. Go to DATA/SHIPS and open a file called Shiparch.ini
hp_gun_special_6 means that "the following hardpoints are class 6".
HpWeapon02 is the name of the hardpoint.
So, that line means that the Hardpoints HpWeapon02 and HpWeapon03 are both class 6 guns. However, you can mount class 5, 4, 3, 2 and 1 weapons on it aswell.