Bicycle Mechanics - Not a newbie, just a dumbass

I'm not much good with bike mechanics, but that doesn't stop me trying. After replacing my derailleur, chain and sawing off my chain guide I discovered that it was a worn cassette that was making my chain skip. I ordered a 9 speed LX cassette to replace whatever was on before (Acera I think). However, having just attempted to remove it I realise it is not as easy as I thought. I have a screwdriver with a bizarrely shaped handle that will fit into that star shaped thing on the smallest cog of the cassette but (if that will do the job) I am not sure how to unscrew it or whatever. If someone could give me some advice it would be useful, bearing in mind that my LBS is by no means local. Also, I've been reading about Uniglide and Hyperglide, will this affect the chances of my cassette fitting to my hub, which is a 98 Acera?

You need to put that tool with the strange shape handle into the end of the cassette. Then put the wheel back on the bike. When you pedal with the chain on the biggest sprocket the handle of the tool will bear against the frame and unscrew the retainer.

You need a couple of specific tools to do the job right. Actually to do it at all. I doubt you'll get anywhere but frustrated with a screwdriver and a hammer.

Check out www.parktool.com for some tool eye candy. There is also a section that is a guide for doing your own repairs. Go here for the area on cassette's and freewheel removal. http://www.parktool.com/repair_help/FAQcogs.shtml

You'll need a chain whip and a cassette tool each about $15.00. You can get these mail order. Try www.performance.com or www.nasbar.com or www.pricepoint.com

Good Luck
L8R

Of course, if the cassette is worn out, so is the chain. If you replace only the cassette, you will not fix the problem. In fact, you will ruin the new cassette very quickly. When you go to buy the cassette tool you need, also get yourself a chain tool.

I already got a new chain. Shimano IG. But it's 7 spd so I'm assuming I will still have to get a new one.

Forgive me if this is a stupid question, but is Acera a 9-speed system? Do you have 9-speed shifters? You can't just stick a 9-speed cassette on with 7 or 8 speed shifters. Well, you can, I guess, if you have an 8-9 speed freehub body, but not if you have a 7sp. And the indexing won't work though you might accidentally hit right on a few cogs. I only ask because you said you had a 7sp chain. If I have misunderstood, please disregard all this.

If you do have a 9sp system you definitely need a 9sp chain. A 7sp will be too wide for the narrower 9sp cog spacing. On the other hand, you can use a 9sp chain on a lower speed system. Sometimes they even work better. I like SRAM chains.
FWIW,
Raymond