Connect your MIDI keyboard to your computer. Use the most convenient connection method applicable. These may include XLR or TRS connector cables and may even involve the use of a third party breakout box.
Save the MIDI file from your keyboard onto your computer hard drive.
Purchase or download a free trial of digital transcription software such as Notation. Install on your computer the digital transcription software of your choosing.
Use the digital transcription software to open the MIDI. This software will provide the sheet notes for your entire MIDI file.