First I replaced the door seals but the water leak persisted. Then I ordered all the spray arms but only replaced the middle and lower arms. This solved the water problem and in taking those two arms apart, I found there to be a good bit of calcium buildup that blocked some of the holes and the angle of the sprays.There were no tools required to replace the arms. The lower seal required removal of many parts, whereas the door seal did not require any tools. I did not replace the upper arm because it requires a pin which was not included with that arm.