This thread is a year old so i know the OP is unlikely to benefit, but for the benefit of anyone trying to remove the fan from an Asus F5GL (X59GL), for replacing/mending/essential dust maintenance... (note: doing any of this will void warranty)
my experience of the fan is that it is difficult to access/remove alone and is much much easier to remove along with the heatsink/heatpipe assembly (secured to the board with 4 screws over the CPU and 2 over the GPU) that's 8 screws total needing removal, plus the 5 needed to initially remove the access panel on the bottom of the laptop. for clarity once the screws are removed the fan, pipe, and heatsink will all slip up and out of the machine.
doing this will, however expose both the CPU and GPU chip, so you will want to keep the dust/static (ground yourself) off of those. My model came shipped with thermal paste on the CPU (first chip after fan along the heat pipe) and a thermal pad on the GPU, the pad i protected with fresh cling film (if yours is dry and useless you'll need to replace with a new pad or better a pasted copper shim) while i worked on the assembly, cleaning all of the dust / cracked dry thermal paste on the cpu etc off & reapplying thermal paste to the CPU chip & copper contact.
as far as i know thats the easiest way to maintain the fan & can keep your thermal paste fresh while you're at it.