Let me statt by saying that I`m certainly no wrench. I was cleaning my chain and sprocket today and was wondering if they needed replacing. I have to admit pretty much ignorance to chain slack, tooth wear, chain stretching etc... I`ve read the manual and posts but I still feel like I`m guessing half the time. I`m embarassed to say that I also don`t know how to get the rear sprocket off. Where I expected bolts, I see some sort of foreign (to me), fastener. Is replacing both sprockets and chain something I can reasonably expect to do myself (see first sentence)? Thoughts on changing my current 40T sprocket for a 41T? Also, what should I reasonably expect to pay for these parts. I see prices all over the place online. Any and all suggestions appreciated!

From the other side dude with a good metric allen key!
Have a look inside the wheel hub from the other end.
Make sure to do them up properly as per spec and use some locktite as they are know to come loose and make a mess of swing arm, hub.

All looks OK, so it's ok to change rear sprocket only. If worn you need to replace ALL 3 components (front and rear sprocket and chain) together or one will wear the others out.

You can easily do it yourself unless you have 2 left hands. Take the rear wheel out, pull the sprocket-crush drive out of the wheel.
Put sprocket in a vice with soft jaws which makes it easier to undo the bolts or work on a bench, whatever suits.
Undo the said allen bolts and the sprocket comes off. Fit the new one in reverse order and make sure it is properly flat /square.
As said use locktite to secure bolts.
Fit wheel and if you look at the stop blocks, they can be fitted the other way arround if the chain is too tight or too long. That is for the originals, the ones you have obviously not...
If you have problems aligning the rear brake caliper bracket put a bit of wood under the tyre so the axle is aligned and then slot it in. It stops you lifting the wheel and gives you a hand free to align the bracket and slot the axle in.

(second edit, it pays to be fully awake to write how to's... )

My first thoughts are that you should leave this to a proffesional.
You need not be embaressed about your wrenching ability, or non ability.
It would be great for you to establish a relationship with a caring service provider. Many in the know are pleased to pass on helpful knowledge. Ask if you can watch for education and that you will stand aside and leave the worker free to do his job and explain important tasks. If you have bike nights, find a willing and generous rider to suggest and you may get a few pointers over a beer or two in your garage. Your attitude is great, instead of acting like a stud, puller of the miraculous, you are ready and willing to admit your greenness.
I have seen simple steps go major arai and chain replacement failure cause a case of case replacement needs and a scary on track debacle.
Not trying to scare, just make aware.

x 2 MUST USE LOCKTIGHT ON SPROCKET NUTS/ BOLTS....as they will come undone otherwise

Thanks for the replies fellas. A big part of my push to do my own work is having the personal satisfaction, but also because I've been less than impressed by the work at local shops. Too often I've picked my bike up and noticed missing bolts and other oversights. The last time it happened I told myself I would not take it back. I was extremely frustrated to be paying a professional good money to have a job done right only to notice his mistakes. Makes me wonder what else has been botched that I haven't noticed. As well, my bike would be in his shop for far too long. I think when the time is right I'll invite a more mechanicaly inclined friend over and tackle the job myself.

Does anyone purchased their chain and spockets as a package deal? I"m still curious to know what is a competitive price

Too bad you're not on this side of the GTA or you could come by here to do it. I'm no mechanic but try to do everything (except forks, primarily because I don't have the tools for that... yet) on my bikes myself. The sprocket change is simple, just take your time, listen to advice, follow your shop manual AND USE LOCTITE.

I'm replacing my chain this week primarily because when I got the bike last year I found it to be a clip link (good on my dirt bike, not too comfortable with it on my street bike), a no-name brand (that I can't source a rivet link master link for), and to have a bit of rust on the side plates. The chain is showing no sign of wear, but I'll have a warm fuzzy when the DID chain is on. All that said, both of my sprockets look to be in great shape so I'm leaving them on (although the previous owner re-geared the rear to a 41T).

I paid $140 for the DID X-ring. No great deal but pretty standard (and I just noticed, cheaper than even motorcyclesuperstore.com). I would have gone for the O-ring chain at $110 as I don't buy into the X-ring hype, but I was standing in Royal Distributing getting a dirt bike helmet for my son and they only had the O-ring in silver... vanity got the best of me and I wanted black. The X-ring came in gold so...