Clint looked at Tony's unconscious body and then back at Doctor Strange, whose hand was shaking, and slowly raised his index finger. Clint knew what he had to do.
As Thanos put the final infinity stone in the gauntlet he grabbed the gauntlet. To Thanos, it looked like he was trying to tear it off his hand. Thanos's knee slammed into his stomach, but it didn't do as much damage as it would've if he wasn't wearing the suit Tony made for him.
Thanos smacked Clint's head and pushed him away. Unknown to him Clint had managed to grab the infinity stones.
Thanos looked over at Clint before looking back at the gauntlet he was wearing, - Finally, after all these years he had them all, he was about to win - and then said, "I am… inevitable." He snapped his fingers, but nothing happened. Confused, he turned his hand and saw that the stones were no longer there.
He looked over at Barton. The infinity stones were in the miniature version of the gauntlet that Clint had.
Clint sighed heavily, he could feel the power of the infinity stones, "What, you didn't see that coming?"
SNAP...
When Tony finally opened his eyes. He looked around to see that Thanos's army was turning into… dust? Confused, he looked at his hand. Nothing. He turned his head and saw Clint trying to stand up, but he immediately fell on his knees when he did and started coughing.
Tony stood up and rushed over to help the archer. Had Clint done it? "What did you do?" He asked,
"I… had too." No. Tony shook his head, it was supposed to have been him. Not Clint.
"I need you to stay awake Clint, we can help you." He said, hopefully.
"No.." Clint choked out, "Tell Laura that I…"
"Friday?" He asked,
"Life functions critical." She replied. Tony was completely unaware that they were surrounded by other people until Steve came by his side and also got on his knees.
"Hey, Clint?" Steve asked,
"Hey," Clint said very softly that only he and Steve heard.
"Look at me." Steve said softly, "We'll tell them. You can rest now."
And that was all the archer needed to hear he nodded slowly before taking in his final breaths.