upgrading 2010 mercury 2.5hp 4 stroke to 3.5hp

I have the 2.5 motor and I'm trying to find out which parts I need to upgrade to the 3.5 hp motor. Just reading the service manual it shows that they are the same displacement and have the same WOT operating rpm range. I think all I need is a carburetor but I'd like to know from someone else who's done this if it is straightforward and if it is worth it. Im using this motor on a 12 ft. tracker and I like reliability and quietness of the motor but I would like more power. I take my motor on and off the boat each time I use it due to where I park the boat so I'm not interested in upgrading to a bigger motor.