You go to Radio Shack (or other similar type of electronics store.) You purchase a tape-head demagnitizer. $25-35.00 You turn on the demagnetizer and gently rub the end of the demagnetizer against the metal tape heads for about 15-20 seconds. Approach the heads slowly when beginning, and pull the demagnetizer away slowly, when done. The entire process takes about 20-30 seconds. Then clean the heads with isoproyl alcohol (or head cleaning solution) with a Q-tip.