Well, with a barbell there is quite a bit of difference, but with dumbells it might be a harder to reproduce. With a barbell deadlift, you essentially position the bar over the center of your feet, bend at the waist and grip the bar, bend your knees until your shins touch the bar, set your back, and then lift. With dumbells you're lacking the bar to set your shins against... I guess the only way I can think of to describe what to do would be to do most of the bending at your waist, keeping your back straight, and lifting them up. But it is probably going to not be much different from a dumbell squat.
My advice - just barge right into the main freeweight area, find someone who is doing them, and ask them for some pointers