Before you tear apart your card, it'd be a good idea to look at:
1| Your case airflow and if it's lacking.
2| If there is any dirt/debris lodged in your cooler's heatsink assembly. If so then you will be best served by blowing them out or using a small brush to dislodge the dirt/debris.
3| Are you running your games with higher detail settings or have you increased the resolution driving the monitor? if so then you will benefit from reducing the details and the resolution to reduce temps.
4| You may want to pass on your full system's specs inclusive of your OS and the display's make and model.
5| You would need a tube of good branded, quality thermal paste at hand before your take the GPU apart but please do note, you shouldn't remove the thermal pads unless you have the exact thermal pads thickness at your disposal. This si why I asked for your specs, the GPU's make and model will help reveal more info on how to disassemble it.
6| Are you yet under warranty with the GPU?