2001 Chevy Impala How do I fix this?

ok so its ok in the winter when the A/C doesnt blow cold on the passenger side but now that its hot my wife refuses to ride in my car so im stuck in a van....not where i want to be....how do i fix the passenger side A/C to where it blows cold when i want it to? thanks in advance for the help

Shawn Hathaway