You can do it with 2 ways.
1. The software way , the program will introduce to you to do it automatically ,by it's own.You should find the utility in your HP folder,inside the Start Menu.
2. The easy way (my way) of doing it is to take pure alcohol (or fire water) higher than 75% clear, and put it on a cloth that you don't want to use anymore,take off the carriage and wash it with the cloth & the alcohol by rubbing it slowly a few times for 1-2 minutes and it's done.
Put it inside again and all will be good to go.