To remove the stock cooler, we will have to remove the screws from the back of the PCB; not all screws are equal in size though, especially the one on the top of the GPU and the two additional ones on the metallic shield:

After we make sure that all the screws have been removed, we will proceed to the removal of the large top heatsink:

The next step that we can take is to install the supplied heatsinks onto the VRM and memory:

All sinks have under them a double sided adhesive tape which is covered initially with a green plastic film; before installing these, make sure that the surfaces are clean from previous residues:

After the installation of each heatsink, we must keep pressed on it a little while so full contact would be obtained; with the stock PCB design, we only had to use one heatsink for the VRM and it must be fixed in the same way, ideally by pressing with a small spudger between the heatsink fins:

Here are some close photos of the attached sinks: