The laptop coolers on my Clevo W870CU are not very quiet, especially when gaming.
Is it possible to replace the laptop cooler with a quieter cooler that still has the same air flow?
One option is to get some canned air and just clean out the vents as best you can. This will often improve airflow and reduce friction on the existing fan enough to make a noticeable improvement in the noise level.
it would be easier to get an external laptop fan. I have one made by antec that cools it down by quite a bit. The best thing about this is that they are easily replaceable, unlike laptop fans
There are some DIY projects that have liquid-cooling at their core. This obviously reduces the temperature, but a savvy hobbyist could simply modify the project to remove the fans completely and run only a liquid-cooling setup.
Obviously this renders the laptop more of a desktop, but it does answer the question. For a more portable solution, as the other answers state, a good gaming laptop cooling pad is the best option.
In general: No. You buy/trash a laptop 'as it'. You can't 'mod' it. The only thing you can do is to buy an external cooler (fans). The other thing you can do is to open your laptop and 'clean' fans from dust.