Thanks for the above comments. Not what I was hoping to hear. Getting the bolts out is not the problem because they are bolted up from underneath and whilst a dirty/mucky job, they will come out (the ones that I have tried so far) with an air impact driver. The problem seems to be that when the floor was installed some the places where it was not possible drill the floor (round the wheel arches and doorway etc.) or leveling was required packers and some form of glue were used. The glue looks like some form of PU adhesive, but probably developed on another planet as it is very tough and sticks like ???? Geoff.