Well first off the previous answer was correct in that Access cannot read FileMaker files. Unless you have some
very specific need to down grade the capability you probably should not be converting to Access, instead use
the greater capability of FileMaker which goes beyond Access.
That being said, if you really do have some solid and necessary reason to convert you can us the utility FMpro Migrator which is a great tool for Migration to and From FileMaker Pro.
Keep in mind the more complex the database structure the more prep work you may have to do or clean up after the