MP3 player without any shield

hey Arduinions ,
can you please help me in my project, I want to make a MP3 player with these components

1)arduino due / mega 2560 / uno
2)ethernet shield for the SD functionality
3)a small speaker 3.3v

I dont want to use a shield , so if anyone knows then please help me.

Thankyou

You'll need -

A DAC (digital-to-analog converter).
An amplifier to drive the speaker.

2)ethernet shield for the SD functionality

What? Is that for an SD card to hold the MP3 files? What's that got to do with Ethernet? (You WILL need additional memory to store the MP3s.)

I have no idea if the Arduino is fast-enough to decode MP3s or fast-enough to run Ethernet and decode MP3s at the same time. I believe the MP3 decoding is normally done by a decoder chip on the shield.

MP3 decoding is usually done with an external chip, whose supplier has a license for the MP3 decoding software.
Example
http://www.vlsi.fi/en/products/vs1053.html
Pretty sure you can't get a SRAM limited Atmega chip do all that.
You can have one control an MP3 module with simple Serial.write commands, such as these:

FN-M16P is also a great option with simple serial.
http://flyrontech.com/eproducts/84.html

It can't be done with the components you have, you need more.