In both Firefox and Thunderbird, when you want to open a document in something other than the default registered in the program, they open a file picker. Now in windows I know exactly what to do with this. I navigate to the program in c:/Program Files/ and look for the .EXE file. What do I do in Ubuntu?
For example, I want to set LibreOffice as my default. Yes, it ships as the default but thanks to Canonical I uninstalled it and manually reinstalled it to get rid of that disgusting global menu. My system knows that LibreOffice is the default app to open these files, but now I no longer have .DOCX and .XLSX files opening appropriately from the Mozilla programs. I must download them all to open them. Obviously I can't use the Windows based file picker on a Linux system. Or do I? Where do I navigate to?
How do I get the Mozilla programs to change the helper apps on Ubuntu?