anyone have any tips for getting the "brothers in arms" trophy?

it says it has to be on segomo. which is the last level i believe. but its not unlocked to pick it. is there any way to unlock it with out havin to have a second person there? cause i can get past the first planet with one life on split screen tryin to unlock the last lvl to get the trophy. but the co-op screen size would be much better to work with. split screen sucks >.<

If it's the one where you need to boost; just grab a second controller and start the level without shooting anything and just avoiding everything else.

Edit: sorry, I misread. Just unlock the levels in single-player, then unlock the trophy in split screen (you don't need to finish all levels in split screen, just Segomo).

You need to work through the arcade mode (not easy) then after you unlock or complete segomo (can't remember which) it is then available to do the trophy

in any dificulty? cause i have completed the game on easy. the only trophies i dont have for SSHD are the gold ones xP

You probably have to play it again in normal to get the golden trophies.