How to delete a file from SD card?

Also you have to give permission if you are using >1.6 SDK

uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

in AndroidManifest.xml file

File file = new File(selectedFilePath);
boolean deleted = file.delete();

where selectedFilePath is the path of the file you want to delete - for example:

/sdcard/YourCustomDirectory/ExampleFile.mp3