Remove switch from switched outlet
Take switch B's black wire (black screw) and connect it to the red wire going to the outlet.  All remaining wires connected to switch A and switch B can simply be capped individually as they are now unused.

(edit: this paragraph originally existed to dispute a second answer that has since been deleted) This method of wiring a 3-way uses a 3 conductor cable for common and two travellers to be transported to switch A.   The White between switch A and switch B is not a neutral in this  case.