Freeze plug replacement?

That plug is in the back of the block, one on each side of the deck. They are the 2 silver items just above the seal plate in the picture and to get to it you would normally drop the transmission as there is no way to get to them if it's in place. The converter and flex plate are in the way. The actual repair of the freeze plugs will take about 20 minutes, the labor required to get to them though is about 6 hours. That is to pull the drive shaft, remove the crossmember, unbolt the converter and drop the transmission out. Then you remove the flex-plate, and pull the core plugs, tap in the new ones and reverse the rest. However I would suggest that as those are rotted out it might be a better option to pull the engine out and replace the other plugs in the sides of the block and heads at the same time, they will likely be in the same condition and start leaking soon as well.

Transmission removal is far easier. The engine comes out the top on that car and to get it out you generally remove the engine with the transmission attached, then split them out of the car. It's not a lot of fun with all the extra electronics on modern vehicles.