Look at post #4 to make sure it's a cassette.
IF it's a "standard Shimano compatible cassette. a PARK 5.2 would be the tool.
Just Google cassette removal tool.
(If it's <8 speed, it's "likely" a free wheel.

You'll also need a chain whip to hold the cassette.
https://www.parktool.com/en-us/produ...ng-tool-fr-5-2