Q: a/c works left side but not right on 2000 BMW X5

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
a/c blows cold air from left dash vent but blows warmer as it goes to the passenger side.
(1) Answer
(2) Comments
How do you replace/fill A/C gas?? Do I have to go to a service station or can I 'try' to do it by myself. I really don't feel like getting screwed over by a $500 bill. Thanks!