What kind of pump do i need to get to do this? What are the specific steps? I can't find any details, it just says to evacuate the system before refilling. Also, I believe that you are supposed to leave a vacuum in the system before refill. How much and how do you measure the pressure? I know someone has done this. Thanks!

 

Save yourself a lot of trouble and take it to an A/C specialist. It'll be cheaper and easier in the long run.