As my 1999 Jeep Cherokee XJ randomly over heats and leaks coolant from underneath….
Those were factory plugs, though. It looks like yours has the brass ones (which mine does now too). A little scary that the brass one corroded through. First things first, you’re going to want the brass replacement plugs because they fit in the holes much tighter. DO NOT GET THE STEEL ONES. I repeat, DO NOT GET THE STEEL PLUGS. Ask me why, I dare ya. lol. It’s time consuming but not too bad of a job.
Take off the intake and exhaust manifolds (make sure to get a new gasket), remove the power steering pump bolts and set it to the side, airbox, etc. and you should have access to them. I used a big piece of brass and a hammer to tap the new ones in after steel-wooling junk out of the holes. I also used Indian Head gasket maker stuff around the new plugs. It would be helpful to have a socket the size of the freeze plug–you want to make sure you push them in evenly.