Need to fix toilet that moves?
Probably just needs new seal. Get someone to help you with the following. 
You will need: 1 wax ring, putty knife, plunger, wrench, new hold down screws if old ones are rusty, towel or small container, trash bag.
 Cut water valve off, flush toilet to empty tank, use plunger to remove last bit of water in bowl, place small container or towel under tank incase excess water drips, then unhook water line from toilet. Place tank lid in a safe place so it wont get broken. Remove the two hold down nuts on either side of the commode. Lift toilet and Lay the toilet on its side . Take putty knife and scrape old ring off bottom of toilet then scrape and clean the flange in floor. Place new ring on the bottom of the toilet. Replace toilet on flange and put on new hold down nuts. Hook water line back up. Good luck.