I am certified repair technician and work for myself as well as a company called iCracked. iCracked has training videos available to watch to learn how to do the repairs. There are also many other videos out on the Net that are very helpful. I also have some .pdfs that may be helpful for you if I know which models you want to work with. Each model is different so it is important to make sure you are looking at the correct one for the device you are working with. It is also imperative that when you are working with these devices, you take care not to damage any of the tiny flex cables or their sockets. Let me know if there is something in particular you would like to view.