Start your notebook and press F12 to enter boot menu.
When the boot menu is shown on the screen open optical disc drive and put first disc inside.
Choose CD/DVD drive on teh list and press ENTER button.
ODD will start to read data saved on the disc and recovery installation should start. It starts with main menu.
How it looks like you can see on
http://aps2.toshiba-tro.de/kb0/HTD1303440001R01.htm
Just follow the menu and continue with installation.
If you have more questions you are welcome.