You'll need a handheld electric mixer for this or a stand mixer with the whisk attachment. Whatever you're using, put the bowl and the whisk in the fridge for about 10 minutes before you start whipping so they are properly chilled too before you use them.
Then just whisk all ingredients together - about 30 seconds on low speed to give them a good stir, switching to high speed until stiff peak (or until you reach the desired consistency you want - I use a stand mixer and it takes me about 2 minutes to get to soft peak stage, then another minute or so to stiff peak, which is what I want). Be careful not to overbeat though...you might end up with butter!