Use this guide to replace a broken, cracked, or defective display on your '''Apple Watch Series 3'''.
Make sure to update your Apple Watch to '''watchOS 5''' or later (and the paired iPhone to '''iOS 12''' or later) to avoid pairing issues after a display replacement.
Replacing the display can cause issues with '''Apple Pay'''. If possible, to reduce the likelihood of problems, delete all your Apple Pay account info before the replacement, and then re-enter it with the new display installed.
This guide shows the procedure on the standard, GPS-only version of the watch, but the cellular/LTE version is similar. Any important differences are noted in the text.