Download and install any free FLAC converter software (see Resources below for an example).
In the FLAC converter software, browse to the folder where you have your FLAC files and select the FLAC files that you want on your audio CD.
The FLAC converter software should have a choice of encoding or decoding the FLAC files. In this case you will want to decode the FLAC files to a folder of your choice. Click "Decode" in the software. The FLAC files will start to convert to WAV files. Take note of the folder where you save the decoded FLAC files. In most cases it is easier to decode the files into the same folder as the original FLAC files.
Open the audio CD-burning software of your choice.
Select the folder where you saved your WAV files. If you saved the WAV files in the same folder as your old FLAC files, you should only be able to select the WAV files for burning. If you see duplicate files in this folder, make sure you select the WAV files to burn.
Import the WAV files to the CD burning software.
Insert a blank disk in your CD drive and click "Burn" or "Write" in the CD-burning software. Once the disc is finished burning, you will now be able to listen to your FLAC files on any CD stereo system.