Here's what worked for me when removing the clips:
Insert a screwdriver into the slot & push down & tilt the top of the screwdriver forward. At the same time, apply thumb pressure to push the top of the radiator down, & with the index finger, push the front of the clip back. The notch on the bottom (green arrow) clips on the sheet ****l edge underneath. The plastic support clip will now pull straight up out of its socket in the radiator. The radiator sits in by gravity. With the top clips, coolant hoses, & transmission cooler lines (if applicable) removed, the radiator simply lifts straight out. Remove the fan shroud & fan/viscous clutch assembly first. Ref. Link (Click Here) for fan clutch removal. Check back in a few days & I'll show more jpegs of the lower radiator supports. To install the clip, I simply pushed down & forward at the same time with a screwdriver in the slot. Correctly installed clip: If you're having trouble breaking them, then push the radiator down at the same time to compress the rubber support feet which are on the lower 1/3 of the radiator end caps. Click Here for new clips.