Dried snot/ hard?

My LO got a bad cold for the first time and his little nostrils are all hard and dried snotty! He will not and I mean will not let me try to do anything to get it out! He screams! Rolls away from me? Fights me! I just can’t do anything so I’m desperate for tips/ help! And no I can’t have someone hold him down as I’m on my own!