How do I get the water out of the phone if the back doesn't open?

Hi

Sorry to hear about your phone but we need to act fast!

Here’s what to try!

You need to open a iPhone from the front

At the bottom you will see 2 pentalobe screws that you need to remove then follow this guide

iPhone SE 스크린 교체

Then follow this guide to remove the logic board

iPhone SE Logic Board Replacement

Once you have the logic board out you will need to clean it with isopropyl alcohol and make sure to remove the metal shields to clean any corrosion off

If this doesn’t work maybe take it to a repair shop that specialises in board repair

Hopefully this answers your question

Thanks:-)