Which type lockring removal tool do I need I'm trying to learn DIY cassette removal as I want to swap one on a buckled wheel. I have another cassette which uses an FR5 but it doesn't fit this one.

When checking this site it looks like it's a HCW-17 tool but specifically mentions that's for single speed bikes which this is not.  It also says it should have 2-8 splines but mine (and the one in the picture on the site) has 9 splines.

This tool is a fair bit more expensive than the FR-5 tool so I just want to make sure it's the right one before I go ahead.

Any help would be appreciated
I think the smallest sprocket is the lockring on this cassette. I believe you need two chainwhips to remove it.

The smallest sprocket looks very badly worn. I'd replace this cassette rather than re-use.