Initially you need to have MediaHuman Music Converter installed on your computer. Please, download installation file using this link. When download will be completed start downloaded setup file and follow instructions during installation process.
Start iTunes and authorize your computer with your login name and password. It is accessible from Store -> Authorize this computer program menu of iTunes.
Make sure your M4P file is played in iTunes. For this open it in iTunes and press Play button
If the file plays fine, then it is possible to convert it to MP3.
It's time to start MediaHuman Music Converter.
At first, select the output folder, where converted files will be placed. You can enter it manually or by pressing the Browse button and selecting the folder.
Also, you need to choose profile with output format (i.e. MP3 44KHz Stereo 128kbps) and it's settings among of pre-defined. If there is no profile which meets your needs you can build your own. To do it select 
at the left side of main window. Create new, set desired settings, name it and save. Return to initial state by pressing 
and choose your newly created profile.
Now you need to add some files you want to convert. This can be done by adding files one by one or by adding the whole folder with M4P files.
To add one or more files press 
button. In appeared dialog browse and select all M4P files you want to convert.
Press Open button and your files will be added to the list for conversion.
To add folder and all its subfolders press 
buton then locate folder where your tracks are stored.
Press OK button and your files in selected folder (with subfolders) will be added to the list for conversion.
Another way to add files is by adding them using drag-and-drop method. Just drag and drop desired files on the main window of MediaHuman Music Converter and they will be ready to convert.
Once your files are added you can start process of converting them to MP3 format. To do it press the Start button. Conversion of files which are selected in list will be started.
When conversion process is started MediaHuman Music Converter will display the progress of conversion.
At the bottom left corner of program's window the total progress of conversion is displayed.
While conversion is in progress you still able to add more tracks to convert. To do it press and repeat steps of adding files and starting of conversions.
Warning! Do not start other programs while conversion process is in progress. It can cause loss of quality of converted audio files.
If you don't remember where converted file is placed right click on it and select Show converted in appeared context menu.
If you are satisfied with MediaHuman Music Converter get the full version in order to use the program without restrictions.
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