You will need a smell training kit and somewhere quiet to sit. For best results you should consistently smell train twice a day for a minimum of four months.
Open a jar and hold it close to your nose. Take quick, gentle 'bunny' sniffs for 20 seconds. Really concentrate on what you are doing - focus your thoughts on what it is you are trying to smell. Be as attentive as you can and really try to 'find' that smell.
Relax, take a few breaths and move on to the next fragrance.
Work through all four fragrances in turn.