It looks like public transportation is fairly easy, but do remember to update with the actual dates you are planning. Also, the Lego Store is located inside Lego House, you should spend some hours touring that while you are there - its great fun! And there is a museum in the basement, don't forget about that. But make sure Lego House is open on the day you plan to visit, and it's recommended to buy the entrance ticket in advance, as there is only a certain amount of tickets for each day. Other than Lego House, you could stroll around the city center and see a lot of Lego buildings from the outside, including the original building (that they made the Exclusive Set #4000007 from).