Requests - Step by step to remove "Memory Heat sink"

Hi all,

My wish is a "Step By Step"- guide for changing the memory "Heat Sink".

My fanspeed is going up and down, pending between 300 rpm - to 2000 rpm.

The computer has been running with both AHT and calibrated with ASD.

After lots of reading about "Fan noise Problems" and test and calibration I have found out that the memory heat sink is the problem. It is placed on backside of the motherboard, on a own board, and its not possible to see it with optisk viewe.

To change it, the motherboard must bee removed.

MY QUESTION IS:

- Do I have to remove the liquid cooling system, to remove the motherboard, or not?

- What parts, and what screws has to removed for getting the motherboard loose?

Please advice with experience.

NOTE:

After lots of reading I have find out that Fan-noise is a common problem on G5 power mac, especcially on G5 2 - 2,5 GHz (2004). On one of my G5/2,5GHz(2004) (have 3 G5 = 1.8 (2004) + 2.3(late 2005) + 2.5(2004) the fan go up and down, and the Memory Heatsink gives unrealistic high temp,(65° Celsius ) from the second G5 start.

I think its a accurancy-related-problem, on the memory heat sink.

Is it possible to by a Memory Heat Sink as parts?