xm wet floor warning

[drkstuart]

the drivers side floor was wet and i automatically thought that it was the heater matrix.wrong.the footoperated hand brake mechanism had been rubbing on one of the alluminium heater supply pipes and worn a minute hole in it.i can see that this job is going to be harder than replacing the matrix.does anyone have any idea how to free up the screw that holds the pipes to the heater matrix?the screw in mine is seized solid.