There are two bolts that hold toilet to the floor.
Pop the caps that cover them and unscrew the nuts off these two studs that stick up through the base of toilet.
Shut off water to the toilet and remove water line from the tank.
To make toilet lighter, sponge all water out of tank and toilet bowl.
Pull toilet up, and inspect the underside of toilet and/or inspect the piping the toilet hooks to.
You will need to replace the wax ring underneath toilet that keeps water and sewage from emitting from connection.
It sounds like alot, but it can be done. There is no guarantee that it is in the toilet or the pipe below it, it might of made its way to the sewer by now.