Right, I have just done my wife's corsa headlamp bulbs, it is a 2005 facelift model, with the ellipsoidal lamps. You can probably get at the dip beam, but definately have to remove the lams to change the full beam or the side light bulbs. To get at the white cover, either remove the hose on the air intake behind the right side lamp, or remove the fuse cover for the left hand side one.

To remove the bumper:

• 3 bolts on top of grill under the bonnet, along the top of the crash beam between the headlamps (easy)
• 3 plastic plugs underneath the bumper (reasonabley easy) pull out the cenre section pin which releases the grip on the plug)
• at the bottom of each wheel arch where the bumper joins, there is a screw (easy)
• At the wheel arch where the bumper joins at the top, there is a screw to remove. This is held in place by the plastic trim around the wheel arch, and keeps the upper part of the bumper in. (reasonably easy but fiddly)

The bumper then pulls off, and you can get at the lamps - 4 bolts to remove and it drops out. Taks off the main wiring plug (there is a red bit that pulls up and releases the plug).

No problem changing bulbs now. I would suggest you do the other lamp bulbs too, as you have done the hard part to get at the unit.

Bulbs are halogen H7.