Reassembly requires a certain degree of manual dexterity but don't worry because after you do it a few times, you will get much better. After you push the spring and plunger back into the mag, it will be under a good amount of spring tension so do not put your face directly over it in case you lose control. You do not want the spring/plunger flying out and hitting you in an eye. Also, be sure you put the button in the correct side: I found out it can be put in the wrong side.