1. Take a music staff paper and write the treble clef for the right hand, the bass clef for the left hand, and the bass clef for the pedals. Connect the 3 staves into a system.
2. Add a key signature (F sharp) and a meter signature (3/4).
3. Write the Violin I part in the right hand with the stems up in triplets.
4. Write the Violin II part in the right hand with the stems down. Be aware, that according to the usual practice in Bach's time, in the original score this part is notated using dotted eight notes and sixteenths which should be played together with the last note of each group of three notes in the top voice. When you transcribe it in the right hand part, you can use groups of quarter and eighth notes in triplets.
5. Write the Soprano part in the left hand one octave lower. This way the chorale tune will sound in a tenor range. The chorale tune will sound well on a solo registration, such as a soft reed.
6. Write the Cello part in the pedals which will be played using soft 16' and 8' stops.
The Violin II part will fit nicely to the right hand part. Although there are some voice crossings between the two violins, in general, the right hand can play these two voices very easily. You can play this part using flutes 8' and 4'.
Because in this arrangement you have to play 2 voices in the right hand, for some people who have little proper organ training experience it might not be as easy as it may seem. If you are at the beginning stages of organ playing, I recommend the 3 part version which will also sound very well. Just omit the step 4.
If you want to learn this piece in 10 days while working only 30 minutes a day, you can download my fully edited instructional 3-part arrangement of this composition from here. It comes with complete fingering, pedaling, articulation, tempo and registration suggestions and detailed step-by-step practice plan.
After the process of arranging this fantastic piece for the organ you will know how the piece is put together on a much deeper level than before which will also help you to advance in the field of music theory.
You can play your arrangement from the written down version on paper or you can use your favorite music notation software to transcribe it. Choose whatever is more comfortable for you but do not forget to treat your arrangement as a genuine organ composition while you play and practice it.
By the way, do you want to learn to play the King of Instruments - the pipe
organ? If so, download my FREE video guide: "How to Master Any Organ Composition" in which I will show you my EXACT steps, techniques, and methods that I use to practice, learn and master any piece of organ music.