My tub faucet is dripping constantly (Delta from early 90's). I live in a condo with shared water main and supposed to ask the HOA to notify the neighbors before shutting off the water. So I would like to find out the replacement cartridge's part/model number and purchase it beforehand to keep the downtime minimal. Is it possible to open up the unit without shutting off the water? If yes, how much of the assembly can I remove? Just the clear plastic ball handle? Is that enough to ID the cartridge? Can I also safely remove the cylindrical housing? What about the ring nut?