Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It only takes a minute to sign up.
Sign up to join this community
I need to remove this freehub (see picture), to replace a broken spoke, however, it is an old bike and I am unsure how to proceed? I've managed to removed the cassette using a chain whip and a 32mm lockring tool.
I do have smaller lockring tool that fits the notch, but it is really tights and do not seem to move at all. Is it even this part I need to loosen to get it off? I can't find any similar freehubs online.. 
That is a neat freeWHEEL that has removable/replaceable cogs. I've never seen one like that in person.
The standard technique is to use the shimano freewheel spline driver tool, and a big 12" or larger adjustable spanner. That's enough about a third of the time
In my experience, the reliable technique is to go straight to a well-mounted bench vise. Clamp the tool in the vise so the splines point upward, lower the wheel down so the splines engage, and then use the full diameter of the rim as leverage. It will unscrew anticlockwise when viewed from above.
It can help to imagine you're trying to spin a large heavy barrel which is on it's end. As for being stuck, this unit has been tightened every time you push a pedal, so yes it will be quite tight.
I've never had the vise trick fail, but its possible there's corrosion and galling in the threads, so some penetrating oil might help too.
It may be hard to find replacement cogs, so you might choose to buy a common freewheel for daily use, and store this weird old one for a future rebuild.
Measure & count number of splines, then search on temu or Amazon. I've had some luck on both. I weld so I have fabricated my own in obsolete situations. I do not think that your is obsolete so good luck.
