Hello,
Before making any upgrades, make the backup files of component and please do full export.
At first please check upgrade/update process at the test website!
If you have custom changes of component, you can lose your changes.
Please, in that case do not make update.
Photos are stored in the folder /components/com_realestatemanager/photos. Make sorted by name. You will see the original image and a thumbnail. You can delete thumbnails (they will be created again if necessary).
See screenshot. Red color allocates original (they can not be removed), and the green color allocates thumbnail (you can delete them)
If you would like any further information, please do not hesitate to contact us too.
Thanks,
OrdaSoft team
RomanD