How do you fit speakers in a Vauxhall corsa?

Think you need to expand on what you wish to do.Corsa's already have at least a base and a treble speaker in each front door for the standard fit stereo. Most extra speakers are put into the rear parcel shelf,or a ready made "custom" shelf is fitted with speakers already fitted.You generally need an upgrade on the stereo to drive these usually powerful extra's. *Some Corsa's also have speakers in the side panels of the "boot".These could be used to upgrade one without them.