I just did a conversion for $15, which was the cost of the SS chainring bolts. I just ripped off all the deraillers, shifters. Then I took off the unused chainrings (didn't want to take crank off so I just took a hacksaw to the smallest one haha).

I actually put a whole new rear wheel on it b/c i didn't want to mess w/ redishing, but I got the wheel for free from a friend who stripped the FG side of his flipflop hub.