I have these two free wheels. Left is Winner Pro, right is Micro Lite (all alloy, 164 g). Both are 13-19. I'd like to change each to a 23T big cog, which I suppose means finding and changing out the two or three biggest cogs.

I've never done anything with a freewheel before, other than remove/ install them and drip oil into them. Swapping cogs is a black art to me.

So . . .

- generally, how do these come apart? I assume the brass lock ring unscrews, the small cog unscrews, the remaining cogs either unscrew, or slide off if splined?
- what tools are needed, and where might I find them? The Winner Pro appears to take a four prong freewheel tool (I assume Park makes it) and a pin wrench (I have one that might fit). The Micro Lite needs a special six prong tool, where are those to be found? What is the tool used for its lock ring?
- the cogs will not interchange between these two, I assume.
- for loose cogs, basically search coop bins or eBay?