Use an audio converter app or website
Open the WMA file in the converter
Select MP3 as the output format
Choose the desired quality or bitrate
Start the conversion
Save the converted MP3 file
Use VLC Media Player to convert WMA to MP3
Use Audacity with the FFmpeg plugin to import WMA and export as MP3
Use Windows Media Player if supported by your setup
Use an online converter if you do not want to install software
Use a desktop converter for batch conversion of multiple files