There maybe enough slack to just pull the sprocket off then you wouldnt have to. maybe not. Start by taking out the bolt for the sprocket and go from there, if you have to loosen your chain then do it. Might not be a bad idea anyway because then you can adjust your chain for your new sprocket if you have to.
Im pretty sure it is like the 700. There are allen bolts on your swing arm by the axle carrier, Just stand behind your quad and look down at the back of the swing arm. You would loosen those.
I have not dont this on my 700 because it is new but on the left side of the axle carrier you should be able to adjust it back and forth to loosen or tighten your chain and I think you may need a special tool. On my Honda 450 it is the same way and it requires a special tool but my aftermarket carrier came with one.
On the rear of the swing arm on the left side (just to the right of your chain and sprocket) there is an adjuster to move back and forth to tighten and loosen. Most of the time there are holes in it you stick a big pin tool or even an allen in to adjust.
I just went out and lloked at my Raptor but didnt see any holes in the axle carrier just like a knotch that looked like it would require a special tool.