If you have all of the Stud Multiplier Red Bricks, you should by now, then you will achieve True Hero seconds after starting the level. Then just complete the level or Save and Quit and the trophy/achievement will unlock.
Here are all the stud multiplier red bricks:
1) X2 Multiplier – 1,000,000 studs
2) X4 Multiplier– 2,000,000 studs
3) X6 Multiplier– 3,000,000 studs
4) X8 Multiplier– 4,000,000 studs
5) X10 Multiplier – 5,000,000 studs
And here is a video walkthrough to obtain them:
Credit to AFGuidesHD