The comment thread on the question has me horrified.Outside the fan, there's no magnets involved, and the question is phrased such that it sounds like the OP is trying to stick a fan directly onto a heat sink, with heat sink compound.
You generally wouldn't be able to buy a regular 'stock' intel heat sink/fan assembly (HSF) seperately as far as I know. They're aluminum on the outside, have a copper 'slug' for a core, and come with an approved heat sink compound pre-applied
In fact, the business end of the heatsink should look just like this. You line up those pins, gently push them in, and you're in business. Assuming its a heat sink for the right socket type - the fastener locations may vary between sockets
That grey rectangle and trapeziums? Heat sink paste. If its bare metal, you'll need to add some. This is a LGA 1150 heatsink I think, but the same basic bimetallic design has been used since late model PIVs. Older ones were a solid chunk of aluminium, and I believe they had pre-applied heat sink compound
If you think there's magnets on your heat sink... you're better off getting someone who knows what he's doing to install the HSF