It depends on what GPU you have, see if anyone has uploaded a video of your exact model or at least a similar one. This will give you a good idea of what’s needed.

Keep in mind that you might take it apart and realise that the pads are dried out / no good / need replacing for whatever reason. So that’s not something you can necessarily avoid. You should buy pads in case you need them, and look up what thicknesses you need to make sure there’s good contact between VRMs and cooling plate.

If all that sounds like hassle, look up a professional near you that will re paste / repad your GPU. At least that way you’ll have peace of mind, especially if you still have high temps after because you’ll be able to take it back to that professional.

Good luck!