@khailcon its a beast to work on. Anyhow, since we do not have any guides I would suggest you look at the teardown [guide|100364|Microsoft Surface Book 2 Teardown - iFixit|new_window=true] and see if you want to go that route. Cleaning it out might actually be beneficial to your cooling issues. Anyhow if you must replace the thermal paste, use something like this guide [guide|744|How to Apply Thermal Paste - iFixit Repair Guide|new_window=true]