Copying data from unbootable Macbook
You can use this iFixit guide -or the one for your specific MacBook, if this isn't- to remove the hard drive, but in short:


Remove the lower case
Disconnect the battery (with care, as you may break the connector)
Remove the hard drive


Then put your hard drive on a USB 3 case and you're ready to plug it to any Mac or HFS capable Windows or Linux machine to recover your data.