Edit: Ignore this; my bad

It is certainly a freewheel (if it was a freehub there would be bulge on the drive side of the rear hub) but it's held together like the early cassettes as Homebrew01 said.Removing freewheels is usually an easy process unless you have one that is not designed to be removed. Once you unscrew the fist cog removal may seem more obvious. If not, I would remove the axles (you said you wanted to service the bearings anyway); you will need some cone wrenches of the right size to remove the nuts and cones. Further, I'm guessing here, you may need to pry off that cover around the axle which might expose some splines, otherwise you will need to disassemble the freewheel to remove it.

There is some lettering on the dust cap/ring around the axle; what lettering/ numbers are on the ring?