Not hard at all.
It was interesting.
Getting screws out was easy.
Getting screws back in was tricky, I am serious when i say they are the smallest screws I've ever seen in my life.
So getting them in hole and threading was interesting.
It took 3-5 minutes each side, and I was hysterical laughing the whole time at my inability to see them clearly, to hold them firmly, and to get them threaded.
But it was no biggie.
Had I had a tweezer, whole process would have taken 3 minutes start to finish.
My brother in law is an optometrist, and even he remarked how small the screws were.
I've had 20 people comment on it in the last few days!!!
Plus it cost me under $20 to replace a broken back piece that Apple wanted $175 for!!!!
I may buy a couple more, different ones and change them like accessories depending on which ride I am in!