When removing Tefillin, why do we start by taking off the finger, hand, and two windings of the forearm before removing the shel rosh? The shel yad needs to be on first and last. So why not simply remove the shel rosh right away with none of the shel yad? It's obviously not an "earth-shattering" matter. I'm just curious if there is a special reason for this. When I ask such questions, I generally learn that there is indeed a reason for the procedure. Many thanks. CHODESH TOV! CHAG SHAVUOT SAMEACH!
From the Dirshu halacha email Daf HaYomi B'Halacha Daily Email - 28 Iyar/May 29
"According to the teachings of Kabbalah, the proper way to remove tefillin is by first removing the straps which are wrapped around the middle finger. Then -- because it is forbidden to wear the shel rosh without the shel yad -- the shel rosh is removed, followed by the shel yad. To show the wearer’s reluctance to remove his tefillin, the shel rosh should be removed with the left hand. In certain ways, the tefillin should be removed in the manner that they were put on." [שו"ע כח, ב, מג"א ב, ומשנ"ב ה-ו]
also from 11 Iyar/May 12, "Upon removing the tefillin, one must be careful to remove the shel rosh before the shel yad." [סעיף ו, ס"ק כב, וביה"ל ד"ה פגע]