Sprung Trunk- 83 Celica GT

I have a 1983 Celica GT and while me and my buddy were working on it the trunk was sprung on one side.
We were taking out the tailights with the trunk open.
But we were outside and the wind was blowing the trunk on to us.
SO my friend put a spray paint can in between the trunk hood and left hinge.
When we went to close the trunk the left side was sprung.
It does not close all the way and is definelty not watertight.
Someone told me the only was to fix this was to replace the hinges.
But when i took a look at it, the hinges looked all welded in place and rivited to the frame!
Is there a way to adjust it.
I already adjusted the hood forward and back.
But i need to adjust the left side height, how do i do this?

Please help!
Owen