How to Free up Storage on Google Pixel by Deleting Photos and Videos that have been Uploaded to the Cloud
Google makes it easy to free up phone storage by purging photos and videos that are already stored, for free and in full quality, on Google Photos.
Step 1. Open Google Photos from the home screen or app drawer.
Step 2. Open up side menu by tapping on three-line menu bar or swiping in from the left.
Step 3. Tap “Free up space” in the side menu.
Step 4. Wait for app to tabulate photos stored in the cloud.
Step 5. Tap Remove to delete them from your phone.
These photos and videos will still be available, in their full quality, Google Photos. If you want to download them again to access them locally, just tap on the greyed-out version in Google Photos and tap Download.