I don't know how hard it is to open other iPhones sim card slots, this is our first iPhone. I was holding it with my hand on my leg and I thought it was pretty hard to open with the amount of pressure I was applying with the supplied tool and a paperclip. I eventually opened it when I laid it on it's side on a desk.
After all that work 😛 I found out the sim card from our samsung phone was too big. 😡 Time to either order a micro sim card or use a cutter on the old one.