I could only push down/side and up a bracket from the 478 socket. The second bracket below the first it is easy to remove (not shown in the video), but the 3 and 4 tend to keep push down the first bracket again at random.
I had to remove the motherboard without removing the power cable and restart/sound cables etc. to acces the other two brackets and remove them from the CPU.
You just put the motherboard on some paper pieces, on a parquet board, which sits on the horizontal PC tower (not shown in the video).
I got inspired by the below video, but it is rather low in light and with some mistakes (He/she dind't explained the moves etc.)
Installation and removal of obsolete Intel S478 heatsink
