how to delete mavarick and go back to mountain lion

do you have a backup (time machine or a clone)? If so, then you can restore your backup using a method consistent with the type of backup you have. If you don't, then it gets harder but it can be done. You will need a backup of Mavericks to go back to Mountain Lion and a clone is better for this job.

Look to the right, "More Like This." This question has been asked and answered at least a couple of times every day since the release of Mavericks.

This may help:

https://discussions.apple.com/docs/DOC-6162

Ciao.

Apple's version.

Revert to a Previous OS X