Avoid issues posting and syncing your photos by updating to version 3.9.16 or later of Picasa
Delete albums and photos
You can easily delete individual photos or entire online albums:
Deleting entire albums
- From the My Photos page, click the album you'd like to delete.
- Click Actions > Delete album.
- Click OK to confirm and delete.
Deleting individual photos.
To delete multiple photos at once:
- Click Organize.
- Select the photos you'd like to delete. To select multiple photos, hold the Ctrl key while selecting photos.
- Click the Delete button.
- Click OK to confirm and delete.
To delete an individual photo:
- Click Actions > Delete this photo.
- Click OK to confirm and delete
https://get.google.com/albumarchive/