How can I remove stuck anti-vandal rings in tap head?
if you just need to replace the washers can you


turn off the water
open the tap fully
unscrew the cover flange at the bottom of the tap
fit a pair of mutigrips under the flange and undo the spindle from the breach


hence replacing the washers?
Once you have the spindle out you will find it easier to get at the anti-vandle screw and undo it