With the rivet removed, this piece should wiggle right out. Keep it handy as you will be reusing it again later.
There is a second connector behind this cover. You’ll have to remove it as well.
All told, there are three connectors on the left (passenger) side of the engine compartment that are part of the radiator removal. Welcome to the 21st century. Thankfully, this car is nothing to work on when compared to the most recent BMWs.
Underneath the car, you’ll only have to remove the plastic cover, which is held together by about seven 8mm screws. Some people decide to simply disgard this piece for easier access later but I like to keep things original and reinstall it if I know I won't need to get underneath here again anytime soon.
With the protective cover removed, the oil cooler will be exposed. There are two Torx screws holding this in place. We have to free it of the fan shroud to remove the shroud later. There are two more Torx screws you'll see that hold two plastic bars in place on the oil cooler shroud. Those are to hold the shroud onto the oil cooler, and do not need to be removed.