I learned something today when I tried to remove the interfacing from a tie without removing the thread holding the tie together first.  It can't be done, and I wanted to use the tie whole without the interfacing.  After removing the stitches and interfacing, I will reassemble the tie, possible with a piece of muslin or my favorite HTC interfacing before sewing the seam back up (by hand).  Then I can use the tie for the purpose I intended without the bulk of the heavy interfacing used in the tie construction.