Removing the wheel off a chaincase-equipped DL-1:
Unbolt fender stays, then unbolt fender mount at chainstay bridge. For simplicity's sake, unbolt seat stays entirely and pull the fender and seatstays out as a single unit (no need to go grabbing for the bolt under the seatstay bridge when it's easier to pull the whole thing off).
Remove the slide-on cog protectors on the left side of the chainstay (if they're still present - usually they'd get caught in the spokes and thrown to the wind), then pull the back cover off the chaincase.
Spin chain until you find master link, split master link and thread a spoke through each end of the chain so it doesn't fall into the chaincase. Twine will also suffice. Disconnect Sturmey hub cable, loosen axle nuts, pull wheel.
Reverse process to re-install.