just a tip for first timers, dont throw away the old screws holding the props straight away keep them safe for an emergency, if you happen to loose one when fitting new props, i was thinking more of when you might have to change them in the field with cold hands, you can buy a small tube of thread lock to use on the saved screws before you insert them in the motor only use a very small amount .
its sods law that dictates having more props than screws at the wrong time the reason dji advise using new screws is because they come ready coated with thread lock only use the little screwdriver to tighten them up because something with more torque could strip the thread in the motor just some advice from previous experience with many years in modeling and rc