If you have a bike stand but no vise...

Put an adjustable wrench in the bike stand clamp. Put the freewheel remover tool in the freewheel and use the wrench in the clamp as the 'vise' with a quick release holding it in. Turn wheel. Worked fine for me.

If it's 8sp. then this is the hub and it has a freehub and cassette. Amazon.com : Shimano FH-RM30 Rear Hub - 8-Speed, 36H x 135mm, Quick Release, Silver : Bike Hubs : Sports & Outdoors

A big pipe and a wall will always work wonders.

http://m.youtube.com/watch?v=KVCOjZ4wCgA

a cassette you hold the cog cluster with a chain whip then unscrew the lock ring CCW

there is a too like a freewheel remover but it has a center pin to go in the QR axle to hold it straight

or theres one with a 3/8" socket drive ..

Sometimes freewheels are on REALLY tight, and the usual wrench/bench methods don't work. I grew up in the Eisenhower era and have removed a fair number of freewheels, but a few years ago I couldn't loosen a freewheel on a '90's mountain bike using the bench vise/bus driver method. I thought the freewheel must be cross threaded or corroded on.

I ended up putting the tire back on and waited for a friend to come over. We stood the wheel up on the floor, and put a big socket and 3/4" breaker bar with a 3' cheater pipe on the remover. I hugged the wheel to keep it from turning and he bounced on the end of the pipe. It took a few bounces, but the freewheel did loosen up. When I looked at the threads on the hub, they were very clean (with no sign of grease though) and in perfect condition; the freewheel was just on REALLY tight.

I have since taken off some freewheels using an impact wrench on the remover when I didn't have a vice handy.

It's not a freewheel, Eisenhower.

I would get some good penatraing oil soak the hell out of it and use a cheater bar