This video shows you how to rebuild a Creality K1C with Unicorn nozzle hotend unit instead of replacing the entire hotend. I suspect this will work with any Creality Unicorn nozzle printer.
This process may require a propane torch, heat gun, and wire brush or steel wool. You may need to replace the screws that hold the hotend on and you will need thermal paste/grease.
Here's where I got parts:
Amazon Heater and Thermistor: https://amzn.to/48lUK1i
Amazon Screws: https://amzn.to/3YyiAE0
Amazon Thermal Paste: https://amzn.to/40gtNtV
AliExpress Heater and Thermistor: https://www.aliexpress.us/item/325680...
Propane Torch: https://amzn.to/3UjwIyk
Heat Gun: https://amzn.to/4hkJGFP