You want to use the frequency sweeps on side 1 which are on the label as tracks 2A 2B and 2C. If you just look at the record they are tracks 2, 3 and 4 on side 1.
These are actually degaussing tracks not "demagnetizing" tracks. There are much better instructions/info listed for the Sweep Record on the Cardas site. Cardas should put that info in with the record.