when i do it i dont bother, i leave the car on the deck, undo the top nut and then when i jack it up in the air it takes the weight off the springs, but.... when you undo the two lower bolts you have to give the shock a bit of a knock to get it off the lower arm.
Thats how ive always done it though.. and you wont need them for the coilys...
there are two nuts to undo on the top mount though, i managed to get both mine off with an airgun but you might need them to get the nut off with the shock off the car.