Reinstalling OS X Mountain Lion without Apple ID

I'm selling my Macbook Pro Retina. It originally came with Lion but I was given a free download of Mountain Lion to my Apple account since it was due out near the time of my laptop purchase. I have just erased the hard drive and would like to reinstall Mountain Lion for the person who purchases my laptop. I am unable to reinstall ML without an Apple ID. Since I am going to sell it I don't want to put any of my information on the laptop.

If I put in my Apple ID will they be able to recover it? Maybe I can change my Apple ID password after I install OS X so they couldn't access my account? Is there any way to reinstall without a password? Or do I just have to let the buyer purchase it themselves? Totally lost.