You'll need to grind off the link at the distal end of the 166th link. Then, using a punch, punch out the pin that connects the links. Or get a chain cutting tool(I've never used one) they sell them in motorcycle shops.
The RIGHT way to do it, is to get yourself a Chain Press/Rivet Tool and a Dremmel. You would place the chain on the bike, and measure it's length out, then mark the link(s) that you want to get ride of. Take the chain off the bike and put it in a vice. Dremmel one side of the pin off flush with the last link you need, and push the pin out the other side of the link.
The Ghetto way is to file or dremmel the pin flush, then put it in a vice and beat the pin out of it with a very small screwdriver or punch.
If you aren't able to get your hands on those tools, a trip to the STealership can always be made too. (I HATE having to do that though)