installing sprockets and chain on my 81 kz 650

I sent a forum out yesterday about my chain breaking on my bike. I got some good information back, and it seems the best thing to do is to replace my chain and sprockets. How would begin on replacing my sprockets. I can easily see the back sprocket but how do I get to my front sprocket. I have never work on a bike before and I dont know if I would need specials tools. I do not think my center stand is high to let get to the front sprocket. Also I was wondering if I need to really replace my sprocket since it was my mistake my tighten the chain to much to were it broke. In my eyes my sprocket looks pretty good. But I could be wrong and it may be to orginal sprocket. Do you have any illustrations or suggestions about installing sprockets and chains.

If the chain broke I would venture a guess it was old and worn out, so yes you should replace the sprockets at the same time. It's the best way.

You need to remove the left side cover to get at the front sprocket. The nut size is 1 - 1/16" if I recall correctly. Since you don't have the chain on it and thus can't secure the counter shaft from turning via the chain-rear brake method, I would get an air impact wrench to remove that nut.

mpc, if you've never worked on a bike before, this might be a major challenge for you. Do you have many tools? Off the top of my head, you're going to need an allen wrench to get the cover off, a hammer and chisel (preferred), or a screwdriver to bend the locking washer tabs down. Yes I think OKC_kent is right about the 1-1/16" socket. You can use a long breaker bar with a cheater pipe on it to get it loose. If the chain and sprockets have never been changed before, the nut will be really REALLY tight. Put your old busted chain on the front sprocket, and shove the biggest piece of drill bit that will fit through the chain and turn the sprocket counterclockwise till it locks up against the case, put the socket and breaker bar and cheater pipe on it the nut oriented so that you can hold the bike down with your body and pull up with the bar. Do some warm up dead lifts first. But if you have an air compressor and a decent impact wrench, that'll work a lot easier. What you could do is take the cover off, get the bike to a garage somehow, and get them to use their impact wrench.
When you get that done, you've got the hardest part of the job done.
You still haven't mentioned what bike you have, so we don't know what size chain and sprockets you'll need.

If you have the locking washer that bends over the nut, you might consider getting a new lock washer. I re-used the old one and it broke, the nut came loose, and I couldn't go anywhere.
Fortunately I only had to push the bike 100 yards as I was turning in the drive at work after lunch

Bought a new washer from Z1, robbed a nut from a spare motor, all is good now

you should replace everything at one time, and yes BUY THE NEW LOCK WASHER, I had one fail also, thought the whole tranny blew up when it came apart, plus sitting on the side of the toll road for a hour until I got picked up

Hey thanks for all the ideas on what I should do about my sprocket and chain. By the way the kind of bike I have is a 1981 kz 650 csr its really clean I have to get a picture of it and put it on my profile. Back to buisness. I guest there is a screw that I will have a hard time taking off is this screw on my front sprocket are is the cover screw. I was working on it and all the screws seem to come off pretty good. Im trying to take my clutch lever of its pretty tough to take off. Once I got the bolt loose does it just pull away from the arm? I was not for sure I did not want to strip the little groves that the clutch fits in. I dont have a air impact wrench Hell, I dont really know what that is, but Im thinking you need some type of air compressor. If I can not get an air impact wrench will a socket wrench work with out making the counter shaft turn. What will I have to do to make it work? Can I damage my counter shaft while in the process? Also can you tell me what size sprocket and chain to use. My broke chain is a 630.