How do I remove a 3 inch section of pvc from a 3 inch to 1 inch reducer that I solvent welded together

You'll have to cut it out and replace the pieces. Once glued, they are "one"

Take a hacksaw, or sawzall and cut out the pieces. Even if there was a way, which there is not, to remove the stuck pieces, the sizing would be off and you would not get a good seal. The cement is not just a glue that sticks two things together like elmer's school glue. Pipe CEMENT actually welds the pieces together by melting the plastic a little and dissolving it to a certain point, and when placed together and allowed to dry, becomes one unit.

how do i remove a 3 inch section of pvc from a 3 inch to 1 inch reducer that i solvent welded together

You use a 'Ram-Bit (http://www.plumbingstore.com/pvcsaver.html)'.

Thanks guys