if it's ten speed, i'm assuming it has a thread on freewheel. your options are to either:
A: sieze the freewheel permanently. weld it or remove all the grease and replace it with jb weld.
B: remove the freewheel, dish the wheel over enough to get a track cog to line up *perfectly* with the smaller chainring up front. jb weld the track cog on.
C: get a cheap fixed gear rear wheel. i *might have one i could let go for pretty cheap.
other than that, remove the derailluers and shifters, remove the big chainring if you want(if it's riveted to the middle chainring, just drill out the rivets). i recommend keeping both brakes till you are comfortable with the concept of fixed gear, and even then keeping at least the front brake. you will need pedals with preferably metal toe clips, or clipless pedals, or pedals with power grips. i've used all three and prefer clipless if i know i'm going to be doing a loop back to home, or power grips if i'm going somewhere that would otherwise require me to bring a second set of shoes.
