Hamburg said in a statement on their website that the 28-year-old Peru international was en route to Brazil on Wednesday to complete his medical ahead of a move to the Copa Libertadores champions.
"The two clubs have agreed on a transfer," Hamburg sporting director Frank Arnesen told hsv.de.
"For Paolo, it's a great thing to play for this club. We of course wish him much luck and success."
The move ends Guerrero's six-year association with Hamburg, which delivered 47 goals in 161 Bundesliga appearances. Prior to joining Hamburg in 2006, Guerrero spent four years at Bayern Munich, where he managed 10 goals in 27 top-flight outings.
Guerrero has scored 19 times in 41 international appearances for his country and was the tournament's top scorer as Peru finished third at the 2011 Copa America.