@mitchybemitchin great idea about posting an image of your board. To change your thermal paste, check [https://www.youtube.com/watch?v=l8BfaVhWIi4|this video] Should be the same for your model. [guide|21499]
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!