Excellent service from FLO as usual, with delivery in Switzerland six days after placing the order.
The replacement fan pack contains a chromium plated grill, 8 thin M3 washers, 4 orange coloured silicone rubber O-rings, 4 countersunk-head self tapping screws, slightly longer than the original ones, and the SUNON MagLev HA40101V4-1D11C-A99 fan unit. It was only by reading through a very long thread on cloudynights.com I learned that new cameras are fitted with two O-rings on each screw, hence perhaps why the replacement fan pack comes with four O-rings and longer screws. The rear panel of the camera is separated from the camera body by unscrewing three pan-head chrome bolts, and unplugging the two-pin fan connector, after which it is easy to remove the old fan and mount the replacement.
In my particular case, I thought the fan had failed after four years of very good performance. In fact it had not failed, but was stationary, wedged by a dead wasp. I decided to swap over to the new fan anyway, since it seemed possibly to be marginally quieter in use.