Follow your iPhone's logic board replacement guide to remove the logic board. If you notice corrosion or liquid residue on other parts, follow the appropriate guides to remove those as well.

If you have an iPhone 4 or earlier, you can remove the EMI shields for more thorough cleaning of the chips underneath. iPhone 5 and later models do not have removable EMI shields. If you have a newer iPhone and believe there is damage under the shields, you may need to consult a repair professional.

On an iPhone 4 or older, use a set of tweezers or your fingers to pull off the EMI shields.