Click on the round avatar drop down menu on the top righthand corner of the homepage, click ‘Manage Photos.’
Tick the box above the photo(s) you wish to remove the watermark from
Click on ‘Watermark’ above the photo(s)
Select ‘Remove watermark’
Click ‘ok’ to finish
Note: You can remove watermarks in bulk by ticking the box under the name of the gallery you wish to add watermarks to.
This will automatically select all the images in that gallery then you can click on 'Watermark' and select either ‘Add watermark’ or ‘Remove watermark.’