Initial trimming and fitting upper and lower cowling halves per Text and Figures manual. Front trimming of bottom cowl is close. Front portion of top cowl needs more trim to fit down over bottom cowl at front. Taking little bites at a time. I trimmed joggle on lower cowling to 1" as per the Figures manual. My text manual says to trim to 3/4" which IMHO is not wide enough for fasteners. Maybe the new text manual has been updated. I used a cordless Milwaukee rotary tool and thin Dremel cutoff wheels. These work great.