Judging by your posts, I take it you'd like this to be as clean as possible.

To remove the old HSF, you'll need some plastic scraper tools (Walmart has 'em - Look in cosmetics), and maybe a hairdryer. If you can't scrape and gently pry the HSF off, use the dryer (ON LOW HEAT ONLY!) to warm it up. This should loosen the HSF paste/glue so that you can pry it off more easily.

Now, as for your new HSF...You've really got a few things to consider here. First off, notice that your current GPU fan runs off power drawn from the video card itself. The Blue Orb you've got a pic of down there has a three-pin cable that's designed to be run off the motherboard directly. You can get a 3-pin to 2-pin adapter, or you could extract the wires from the old plug and put the new wires in it instead. Just snip the blue wire - It's a tachometer gauge that tells you how fast the fan is running.

Another problem you'll have, however, is that your Viper V770 doesn't have the typical HSF mounting holes on it. That means that any HSF you buy, you'll have to permanently affix to the card. You could use that Blue Orb, but you'd need to either superglue it on there, or get some thermal epoxy (Arctic Silver makes some good stuff). This also means that you'll never get to use that HSF again...so you might not want to buy a $20 HSF for a card that's past its prime anyway.

Should you decide to do it anyway, and go the superglue route, you'll still need some thermal paste between the HSF and the chipset. Apply it thinly, but leave a bit of space in the corners for the superglue. Put a tiny dab in each, and then press the HSF down firmly onto the chipset while providing support with your other hand underneath. After about thirty seconds, you can set it down and leave it to cure...preferably for a few hours.

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