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The HSF(HeatSinkFan) shown is in the release mode, notice the tab pointing up above the latch point(small rectangle opening) that will go over the tab on the socket/motherboard mount point. You would mount the opposite side first then press down to mount the last tab. Once you have that mounted you would press the top tab and push towards the motherboard to latch the mechanism or lift up to remove. Please look at: http://www.legitreviews.com/article/350/3/
Notice the small tabs on the left & right rails around the processor socket. This is where you would place each of the opening on the HSF mount points(rectangle opening) on the spring arm, you place the first one opposite of the locking mechanism tab then place the last over the tab then rotate down the latch mechanism. Make sure that the processor is square & set in the socket before attaching the HSF. You may need to clean the processor surface and use either a new pad or heat sink compound before mounting HSF.
Please use caution whenever handling the processor and replacing into the socket. Be sure to line up the socket with the processor key and be sure to open the socket latch(lever arm on the bottom of the socket in: http://www.legitreviews.com/article/350/3/
) before attempting to insert/remove the processor. Pins can be easily bent thus causing major issues. Not covered by warranty if damaged by end user.
Your new HSF may differ by latching mechanism. Some use a swing arm latch while others use the technique shown in your link. Varies between manufactures but all must align to AMD AM2 socket specs.