There are 4 metal strips - 2 long and 2 short - (I used 4 L shaped brackets from the local hardware shop and straighten them) connected to the 4 fan fitting holes of the top side of the RAD.
Connected to the RAD using 4 x M4 screws - 5mm(M4 because my RAD used M4 screw but others use M3 as well)
Long strips are on the far side from the inlet & outlet and the short ones are at the near side.
Screws are not fully tightened on the 2 shorter strips, so the strips can be retracted towards the RAD.
There is a ledge between the top cover and the metal part of the case.(You will have to remove the top and front of the case any way)
RAD is inserted with the Long strips fully tightned and long strip side first.
Then using a screw driver from the top fan grill I can extend the shorter strips and tighten the screws.
All 4 strips have double sided tape(stuff that holds RADs) on them so they will stick to the ledge and RAD will not move!
It is easier than it sounds
I also had a 240 RAD in the front