Depending on your performance you may get contracts to move to another team mid-season. This will normally be a quick response contract offers (I got one from Mercedes while driving for Force India). Just accept the contract and move to a different team.
I suggest doing this after "On Demand" and also waiting for the second carrer season beacuse it is very unlikely you will get a good team to offer you a 1st driver seat so you can go for "New Direction" and "Cut Your Losses." If you stay with the same team you can also go for "The Equipment may be the Same."