Shimano freewheels can have the cap removed with pin-tools as well:
Not sure about this particular freewheel, but some of Shimano's freewheels have seals and you won't be able to drip lube into them without disassembly. If you leave the freewheel on the bike, you won't need a freewheel vise.
Just lay the wheel flat, take off the end-cap being careful not to tip the wheel and have the freewheel and its 1,000,000000 tiny ball-bearings fall out. Drip some heavy-old down there, and spin the outside to work the lube all the way to the inner bearings. Re-install cap and you're done!
