First, double-check that all retaining clips or nuts have been completely removed. If it's still stuck, try gently wiggling or rotating the cartridge with pliers or a cartridge puller to break its seal. A small amount of penetrating lubricant can help, but apply it carefully to avoid damage to the valve body or new seals.

Ensure you've turned off the correct water supply valves, ideally both hot and cold lines leading to the shower, or the main house shut-off valve. If it continues to drip, your shut-off valves may be faulty and need repair or replacement themselves before you can safely work on the shower faucet.

Yes, this project is considered beginner-friendly as it primarily involves basic disassembly and reassembly. While the estimated time is 3 hours, a careful beginner should allow a bit more time, especially if the cartridge is stubborn or if they need to locate the main water shut-off. Take your time and follow each step.

It is crucial to use a genuine Delta replacement cartridge or an exact aftermarket equivalent specifically designed for your Delta faucet model. Universal cartridges rarely fit perfectly and can lead to leaks, improper water flow, or difficulty controlling temperature. Always match the model number of your existing cartridge or faucet for the best results.