Honestly, when I pulled out my A/C, all I did was unbolt the high pressure line from the compressor a little bit until it started venting and stood back, it's not a big deal. Use some gloves and you should be fine [or else scrub well afterwards with handcleaner and soft soap]. If you have a schrader valve tool, you could always remove the core from the vent and let it go as well, but it's a different thread than a valve stem for a tire, so you can't just put like an old bike pump fitting and hose on it. [Though a rubber one might work...] But yeah, you'll have to worry more about all the white residue [that comes off with a rag], than going blind as long as you just stand clear and don't take a shot to the face.