I reckon I just saved myself about 150 quid thanks to this place.
When I bought the car - I got a shedload of paperwork with it, and found that the last owner had been advised at the last service to replace the airbox as the screws were seized and they couldn't change the filter.
They had obviously chosen to pass that little job (cost) on to me!
My airbox screws were well seized - but after a search I found a couple of threads that pointed me in the right direction.
So - I Drilled out the old bolt heads and discovered that the bolts were seized at the washer / metal sleeve in the lid.
After I eventually got the lid off (took my time so I didn't damage the plastic) I found could unscrew the remains of the bolts from the housing easily by hand.
The actual inserts in the housing itself were fine.
Some shiny new stainless bolts and washers, and a dollop of copaslip(?) and everything is hunky dory.
cost me about 50p for the bolts and took about an hour tops!
I'll pick up a new filter later.