No, it is not possible (yet). But there are workarounds (not official, try it at your own risk) if you don't want to unpublish the project.

• Check out the file you want to replace.
• Add the new file locally without check in (it needs to have another name)
• Run it through SDL Studio to create SDLXLIFF files
• Delete the old files
• Rename all the new files with the names of the old files (not only SLDXLIFF files but also the ones in the original file format)
• Check in the files (the new files will replace the ones on the server
• Delete in Studio the files you added (you will only delete the file reference, not the file itself because you have given it another name

Try this on a sample project to see if it works for you.

Kind regards

Angelo