the manual shows a procedure for manually retracting the convertible top

What is your question?

the diagram in the owners manual is incomprehensible. there's no indication where on the car I should be looking and the drawings don't look like anything I can find. Any suggestions?

What makes this problem better or worse?

intermittent failure of power retractible top.

How long has your 1998 Porsche Boxster had this problem?

about a month or so.