I desperately need to change several washers in my house. All the taps are “Irwel Fiore”, and they cannot be unscrewed in “normal” fashion. Thre is a tiny hole at the lower part of the spindle top (under it) which seem to fit smaller allen key or something similar. I would be very grateful if anybody can tell me what tool it is that fits this little hole, i.e. what is required to remove the spindle top. Thanks.