Change a few audio recordings (WAV files) from mono to stereo

We accidently recorded an event in mono, could you please edit these files into stereo? Total size of ca 7 GB. I believe this is possible using a so called 'pan' function to copy the audio from the recorded channel to the other (missing) channel. Please see attached file all download links. Please send the files back in 320 kbit mp3 files I would need all files back latest tomorrow (Friday 18-7) if possible? Fixed budget: €30,-