Looks like you'll need one of these and I'd buy one as they come in handy once in a while and saves visiting the LBS and paying daft labour charges.
http://www.ebay.co.uk/itm/Cyclo-Bicycle ... 4d05b6cc5c
If you have no vice you can also unscrew the freewheel by fitting the tool into freewheel,
put the quick-release back through the axle and tighten up the quick release until it
tightens up on the tool then use of a large adjustable spanner hold the wheel secure
in-between your legs and turn it anti clockwise, you may need to give it some grunt
as soon as it turns. Stop! Then slacken off the quick release slightly so you can unscrew
it that bit more, when its free just take out the quick release and unscrew it. Job done.
When you come to putting a freewheel back on make sure the threads are clean and rust
free and put on a layer of 'copper slip' and make sure you don't cross thread the block when re-fitting.
I hate RED DWARF