Transcribing music is the best practice you could ever do. I recommend you do not write it down. Just play it by memory along with the recording. Then you must transpose it by ear to other keys.

Be patient with yourself. But, be persistent as this will probably be the most difficult task you have undertaken. Start small, one note at a time.

I promise it is worth it.

Remember that success is not measured by what you start but rather by what you finish.