How to change the default application for WEBLOC files?
I have found a solution:


Make sure that the Finder is set to show all filename extensions (Finder Preferences → Advanced).
Edit the file name by deleting the “.webloc” filename extension.
Show Info: Lo and behold – the application drop down list is no longer greyed out.

Select the browser of your choice and press the Change All… button.
The default application for opening any WEBLOC file has been changed, whether or not it has the explicit “.webloc” filename extension.