You need a 13mm wrench/socket. I have more 13mm wrenches than any other size as it seems like 90% of the fasteners on this car are 13mm. When you get to the heat exchangers, you'll want a deep offset 13mm wrench and I love my 1/4" drive 13mm swivel socket...a money tool for sure, this one and my stubby 13mm racheting combo wrench are my favorite 13mms. You will also need a screwdriver for the hose clamp on the small hose that goes from the intercooler to the wastegate.
This is easy, and if you're going to DIY on this car, you will be removing and replacing the intercooler A LOT, so get used to it and have fun
Brian B. (aka RarlyL8) once suggested that he'd like his intercooler fastened with velcro since it has to come off and on so much.