I find a bolt on cog the easiest swap out there.
I have 2 allen keys, M5 (cog) and M6 (chain tensioner, rear wheel) in my wallet, all that is needed.
This noon I flipped one (which should be done now and then, to prevent sharkfin teeth that wear faster due to chain harder to disengage teeth).

Some things experienced:
- I had to tap out the hubs flange 6 drilled and threaded holes. For some reason, the original thread caused the bolts to require alot more force to be turned in which stresses the allen keys and may deform/strip the hubs alu thread. My spare wheels hub was the same story, confirming no production tolerance/error. Now riding 3 years without problems since.
- don't use threadlocker - it may damage the alu thread. I put some grease rated for aircraft doors etc on the thread.
- beware of stainless steel bolts - galvanic corrosion can dissolve the alu of the thread. I use 12.9 steel bolts, and protect them well against rust (grease also inside bolt heads).
- Replacing or flipping a cog (measured from wheel already unmounted) is a < 10 min job. Not that problem, I'd say. First losen all a bit (take off tension) with allen key long end, then allen key short end and quickly spin out. Then back in opposite way, tensioned opposing couple at a time. After 1st ride check tension.
- use bolts of length so that they reach the end of the drilled holes. Least thread wear, least chance on stripping and no holes filled with dirt.