Our app have a web hook to auto remove changed files while installing the app, but it does not always work well because web hook is not instant event.
To help you completely remove changes, please follow these steps.
Go to admin Online Store >> Themes.
In Current Themes section click on Actions button and choose Edit Code
1. In section Templates select search.fshprod-labelme-json.liquid file and click to Delete button file (see image bellow)
2. In section Snippets select fshprod-labelme-init.liquid file and click to Delete button file (see image bellow)
3. In section Layouts select theme.liquid file, remove the {% include 'fhsprod-labelme-init' %} in <head> tag section :
Finish!