A/C Wiring Help Needed!

As the summer heat approaches, I am need of help figuring out what needs to be done to connect my a/c to cool the home. The a/c is a window mount type, and from what I can tell, has a 230/30A plug (see pictures). The home has an outside plug that is a 125/250V 50 Amp plug (see picture).. My question is how do I convert the a/c plug to work with the outside socket? I am most likely not going to do this myself, as I know very little about wiring... but I do want to know what needs to be done so that I can understand the process, and that I can insure whoever does do it, does it correctly. I am also wondering an approximate cost based on the number of hours it takes to do this. The circuit breaker box has a 125/250V 50 Amp breaker. Any help appreciated!!!!

Note - The black socket is the 125/250 socket. The white plug is the a/c plug, the red sticker is from the a/c.

 

You don't. That would be unsafe. You changed the breaker to 30 amps and the receptacle to a match the plug on the A/C. Of course the receptacle will need to be moved inside. The better solution is run a new dedicated circuit for your A/C