1.) Check your company's culture / rules / procedures about internal transfer
2.) Ask some close friends, especially who transferred successfuly, his experience of transferring
3.) Be prepared, then try to approach managers who have positions; Mostly I will talk to my manager only after I got promise/offer from other team, and don't want current
manager feel uncomfortable.
Just my 2 cents, and I did not have experience of internal transfer though having friends/colleages who succeed transfering
