The problem with the radiator is that the plastic gets old and weak. It can happen to any of us. Now idling the car for 45 minutes can build up some excess heat since you don't have any air cooling especially with a fan delete. couple that with weak plastic and it looks like a grenade went off under the hood. As for replacement. It took 10 minutes to replace. it was the 2 upper clips ( you do have to remove some screws to get to them ) the hoses and the coolant sensor. (I wish I took pics) then you lift it out. installation is the reverse. when you fill the system there is an air bleed screw that you can use to get the air out. You'll still have some excess air after you run it, but it will bleed out when you open the radiator after you run it.
It isn't difficult to do and believe me when I say the plastic is fragile. It was literally breaking in my hands without difficulty (like a choclate bar)