How to make linux filesystem in single user mode writable:

• Boot linux in single mode (add the kernel option “init=/bin/bash” by editing with grub-load)
  If cant made it, here is a short manuel http://www.cyberciti.biz/faq/grub-boot-into-single-user-mode.
  By the way the single user mode can be use to reset the root password.
• Remount the root-filesystem (use following command “mount -o remount,rw /”)