The instructions included are fairly inclusive and they explain the mounting of every part in a simple manner.
Installing the iCEAGE on a A64 system is very straight forward and not difficult. It's just a matter of lining up the cooler and putting the retention clip on. For a 775 system the installation is a little different, but still very simple. All that is different is using the cradle supplied and the four pegs. The cradle lines up with the four holes in the 775 motherboards, and the pegs fasten it in place. Once the cradle is mounted, the mounting procedure of the cooler is the same as it would be on a 754/939/940/AM2 system.
The retention clip is held on the cooler by two pegs on the base. There's plenty of clearance around the cradle of the motherboard and the base of the cooler. The mounting system is quite well designed, though the clip could have been attached to the cooler to save the hassle of holding it while lining up the cooler. However, it's hardly any big deal, and probably made the packaging of the cooler much easier. One thing I noticed was that the cooler could be easily moved or rotated when mounted. The retention system could be improved in this aspect as well, or having the bracket mounted to the base so the cooler has less possible movement in it.