The steps for replacing insulin refills mainly include opening the cap, unscrewing the refill holder, pouring out the old refill, loading the new refill, tightening the refill holder, and evacuating air bubbles. Insulin pens made by different manufacturers may be used differently. First of all, you need to wash your hands clean and carefully check whether the new refill is intact, whether the color and character of the liquid is abnormal, whether there are any impurities, whether it is within the date of use and so on. Open the cap of the insulin, unscrew the insulin refill holder, pay attention not to let the piston inside fall out, then take out a new insulin refill, load the small end of the refill towards the refill holder, then tighten the refill holder and the pen body connection, install a new needle at the head of the pen, put the pen vertically vertical, screw a few units of insulin, and evacuate the air bubbles. At this time the pen refill replacement is complete. As each manufacturer’s pen is different, the replacement method may be different, you can follow the instructions to replace the refill.