The difficulty of applying a screen protector will depend on the type you choose and your own level of dexterity. Tempered glass screen protectors can be a bit trickier to apply due to their rigidity, but as long as you take your time and follow the instructions, you should be able to get it done without any issues. Plastic film screen protectors are the best when it comes to ease of application, but they will not offer as much protection as tempered glass.