Yikes! I would be saying BYE BYE to those boys.
How long have they been in your care? Have you spoken to the parents about the 5 year olds behaviour?
I really feel for you. When I first opened my daycare in January I had a 6 year old boy who was Before and After school only and boy was that enough for me. I lasted about 2 months with him. He was defiant, didn't want to do anything except play videogames or complain about how bored he was and wreck my toddler toys. I would tell his mom, it would be better then back to it again. Boys that age are difficult.
How many others do you have in care? Do you NEED the money?
For the 5 year old to be saying "hate" that is pretty strong then saying he would be breaking your things? Not worth it IMO.
Good luck and hugs.