Very simple.
1. Start a new Franchise Mode
2. I selected "Manual" for all three Tasks (Might be able to just use 'Manual" on 'General Manager Tasks' and "Auto Manage" for the rest)
3. Select when you want to start your season.
4. When you get to Home screen. Select "Contract Extensions"
5. Select the first player and give him a monster contract you know he will definitely sign. Trophy will pop right after he signs.