@buesrakeklikci use this guide [guide|153671] to get into your ASUS TUF. For more details on the fan replacement, use something like [https://www.youtube.com/watch?v=8o3sHbr297s|this video] Clean all the air inlets and cleaning the fans might help but my experience is that it is better to replace them once they become noisey. Worn bearings etc. will lead to prematurely failure and could cause major damage.
At this point you are better off replacing the thermal paste as well. that way you will only have to work once on all of this. Use the generic iFixit guide [guide|744] for that.
Since iFixit does not yet have a guide for the fans etc, and while you work on your laptop, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!