Hi Dylan!
Here you can find the guide regarding how to fix the PS5 from overheating in general: [guide|144843|How to fix PS5 overheating - iFixit Repair Guide|new_window=true]
Here you can find a guide about how to replace the Liquid metal: [guide|170479|How to Apply Liquid Metal in a PlayStation 5 - iFixit Repair Guide|new_window=true]
And here is the guide regarding how to replace the fan: [guide|141723|PlayStation 5 Fan Replacement - iFixit Repair Guide|new_window=true]
If you are not confident enough to fix this by yourself, then my advise is, to bring it to a local repair shop and let them do it for you! It's not very easy if you didn't done it before.