Off the cuff Risk Assessment:-
1) Chance of screwing up without a manual :: > 75%
2) Chance of screwing up
with a manual :: 50%*
Also ... chance of the tech being a "she" :: < 5%
The term "half a chance" is a turn or phrase, an
idiom, and is not (usually) to be taken literally. Substitute the word "opportunity" if you like.

*
According to your reckoning.