I dropped my iPhone 6s in water what do I need to open it up

To open it up, you have to take the two small screws out from the bottom of the phone. You can actually do this using the tip of a knife or with a safety pin. Then you can use your nails to open up the phone and take the screen out.

https://www.youtube.com/watch?v=t7TgGnej...

Here is a link that may help you.

If this is too difficult, you will need a small screwdriver and a prying tool.

https://www.amazon.com/Repair-Opening-To...

Here is a cheap kit that you can purchase containing everything you might need.