hey man you might want to have a shop do it.
anyone can just replace the O-ring for you in whatever line leaked, and go by the car recharge and fill it for ya, but once you take apart a line to install the new o-ring, your letting normal air into the lines, for a/c before you charge it, it needs to be in a vacuum state... so if you do have someone do it for you, make sure they vacuum the system first. i had this done last year in my last car from Tuffys, it cost me like 43 dollars i think, not too bad. just make sure its done right, if you just charge it without vacuum'ing, you can risk contamination in refrigerant and risk ruining the compressor.
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