Or, if the solutions proposed above do not work, make it executable by opening a terminal, navigating to the folder you show in the screenshot and typing
Code:
chmod +x redeclipse.sh
and then execute it by typing
As additional information, you can see the the permissions attached to each file by typing
"r" stands for Readable, "w" for Writeable and "x" for Executable.
You can modify the permissions by swapping the "x" in the first command for the appropriate letter depending on which permission you want to modify, and using "+" if you want to add it and "-" if you want to remove it.