What part do you not understand? is it how to get into the BIOS? if it is then whilst your machine is booting up-watch for a "hit such a key to enter setup" If you can't see it then turn off and whilst its booting up again hold the Esc and Ctrl key and the Delete key at the same time. If this fails try them one at a time. If this fails then try holding down the F (function keys) one at a time until you enter setup.
IRQ is a physical electrical connection and is needed to run sound-cards etc.
Once in the BIOS you will not have a mouse so you will need to use your home and end keys as well as the up and down. follow the instructions you have received only if you are having problems, these so called tune ups can cause more grief then then solve.