Backup data from Macbook pro which won't boot
Surgery....

....pull out the hard drive, install it into an enclosure (a USB External hard drive enclosure) and simply plug it in as an external hard drive for another Mac without losing everything on the hard drive? 

How to remove it:

https://www.ifixit.com/Guide/MacBook+Pro+13-Inch+Unibody+Mid+2010+Hard+Drive+Replacement/4305