Jim,
You're probably going to have to give us a little more information.
How did you go about pressing the middle metal slide into place in the outer fork tube?? It does need to be pressed in place halfway down the outer fork tube, it doesn't just drop into place loosely.
OR some prefer to leave out the middle slide!!
The lower slide (23) goes on the end of the inner fork tube (22) and the inner fork tube goes into the outer fork tube (24) before the middle slide (26) goes into the outer fork tube and is pressed into place.
Then the upper slide (pressed into place), washer, seal (pressed into place), retaining ring, and dust boot (25, 29, 28, 30, 27).
Bolt (32) screws into the damper cartridge (31) to retain the assembly.
Otherwise, just use the same tool that was used on the middle slide to drive the upper slide into place.
It must be driven below the "ledge" level to make room for the washer and seal and retaining spring ring.
dan