Diligum,
You only need a cassette lockring remover and a chain whip, also called a sprocket remover. Assuming the Sunrace is Shimano compatible, you need a Park FR5 lockring remover. The chain whip can be generic - Nashbar or Performance works fine.

Remove the wheel.

Remove the quick release skewer by unscrewing the locknut.

Insert the cassette lockring remover so it engages the splines of the lockring.

Reinstall the QR skewer and screw the locknut on until it just holds the lockring remover in place. Doesn't need to be tight.

Wrap the chain whip around a middle sprocket so that pushing the handle clockwise tightens the chain.

Use a large wrench to just loosen the lockring counterclockwise. Just loosen then stop.

Unscrew the QR skewer locknut a couple of turns. See if the lockring remover can be unscrewed by hand. If not use the wrench to unscrew it just a little more. When it moves by hand only, remove the QR skewer.

Finish unscrewing the lockring.

Remove the cassette.

Install the new cassette.

Reinstall the lockring, using the lockring remover. I use the wrench to tighten it a few clicks until it is good and snug, but it is not necessary to get it extremely tight

Done.

Others please correct or add as necessary.

Regards,
Raymond