On the main menu of Top Spin 4 you will find 'Unlock Overview'. Here is where you can find all the challenges that you have to do throughout the course of playing the game. Each one will give you a reward for completing it. A lot are done in career by playing tournaments with a certain sponsor. There are also a fair few that have to be done in exhibition with certain requirements to complete them. In order to obtain this achievement just complete 75% of the challenges. Your percentage unlocked can be found at the top of the 'Unlock Overview' screen.