If you pick up luggage that means you exit landside - so you have to take the shuttle bus from T1 Arrivals to T2. The free shuttle is faster than the train. The train is 6 mins in length, yes, but a 10 min walk down there, have to buy a ticket, wait for it (up to 12 mins)....so just take the free bus. Then you check in at T2. Once inside T2, to connect to Concourse or T1 from there - you need a boarding pass which must be scanned.