How to change a cassette?
Change your cassette and extend the life of your drivetrain.
Typical tools: Chain whip / Cassette lockring tool / Grease / Degreaser / Adjustable spanner.
Remove rear wheel from bike, remove quick release skewer.
Hold cassette in clockwise direction with a chain whip tool. Turn lockring tool counter-clockwise using an adjustable spanner.
Replace the cassette. it's important to ensure that the spacers and shims all go in their correct position.