I would recommend you to create a staging site (a full copy of live site) and update Royal there. Make sure that everything is ok and only after that update everything on the production site.
We can help you with the update, provide us with temporary wp-admin and FTP access to the staging site. http://prntscr.com/nadsqw
We have updated theme to version 4.7.3 and child theme files. Replace theme and child theme (don’t copy! with overwriting because we removed some files, just replace all the files from folders) on production by the folders from the staging site. Also, we have updated Ultimate Addons, Revolution slider, essential grid and some other bundled plugins.
In future, we would not recommend copying of files from parent theme to chiild theme to change texts only, use translation files for these purposes, for example, http://prntscr.com/nayjas
We have made some changes in theme options (enabled single product gallery, disabled footer demo content etc) so don’t forget to import theme options (Theme Options > Import/Export) from staging to production after themes update http://prntscr.com/naynvj