Slide the plastic trim tube from the outer focus tube.
The factory wrapped a self adhesive aluminum tape to dust seal the
grooves around the focus body. Frequently, this tape has deteriorated and
the adhesive has jammed the focus mechanism.
Remove all traces of tape and sparingly use a solvent to dissolve
all adhesive in the grooves, bushings and tube sufaces. Clean thouroughly.
It is not necessary to replace the tape.
No further disassembly is necessary for this repair.