There are devices designed for this purpose. Otherwise, you'll have to do it by ear. If you must use the latter method, suggest you use a record in good condition and wide dynamic range but one you do not mind damaging. General advice: start with light to medium tonearm weight and antiskate setting. Use the last track on the record, as this is where tonearms start to veer off and distort. You will be listening for clarity without distortion. Use the lightest weight that produces decent sound. Sorry I can't devote more time to this procedure. But doing it by ear is more art than science. Took me several years to get it just right. Do a Google search.