if it's an allen socket you could try hammering on it's head to start wirh - hoepfully helps to shock screw loose and also closes up hex slightly for another go at it. After that as above or a good pair of Mole grips with soft jaws.
Depends how much of the head is available, I assume you haven't sheared the head off yet. Plenty of light oil (3 in 1, wd40, etc), a bit of gentle shocking to break the corrosion, then much of the above with molegrips and/or torx head using lots of small back and forth attempts. if it shears, I might have a stud removal tool that you could borrow (involves drilling the centre of the sheared stud/screw/bolt then using the extractor with a tap wrench, or similar to draw the remainder out). good luck.
Bolts out hammer and screwdriver new stand on sitting perfect all sorted would recommend 1098 stand thanks for all the advice
