As you progress toward Blueville you'll come to a part of the map with a yellow pipe in front of a soccer goal and 4 Reds standing outside a diamond players house. He has locked himself inside and wont come out. If you look up above his front door, there is a diamond tier sign that you can grab and remove, this will cause the Red's to wonder what happened to his Rank. Bring this sign with you to the wall where you can see iron bars and a gap, drop the sign there for now and grab the battery from the other side and using your red gun fire it while aiming at the close by generator, this should shoot the battery right into the power socket and open the door, *optional leave a force cube under the door, otherwise just reuse the battery after the below part is done.
Now that you are on the other side of the wall remove the battery from the door generator and plug it into the other generator on this side which will cause electricity to appear.. Around the level are White Anvils that can conduct electricity and you will need 2 of them, so go find them and bring them back to this part of the level. You should see a small house, your goal is to direct power to the hut so the door opens and you can get inside to meet the other player who is only a bronze tier. He will say he wishes he could be cool and good and woman will flock to him. Take his sign off the wall and bring it to the diamond tier house and put it in its place. This will cause the Red's to leave and should pop the achievement for helping out the other guy.. If you wish you can take the diamond sign to his side and give it to him, though he'll say he doesn't need it but thanks you anyways.
*This partially leads into "Supraball Noob"