Just press L3 and R3 to getherat the same time

By the time you get to the second part you have to assist jump with Sheva in Shanty Town Look up and back and then a emerald is right there.

If playing single player on mercs. You need 40,000 points to achieve the a rank and corrosponding unlockable characters.

If playing two player you need 80,000 points to reach the a rank and unlockable characters

The strongest weapons in the game are sheva's long bow ( one shot kill but can only be used by sheva )

The s&w 500 magnum ( one shot kill on everything except the bosses, but even on them it doesnt take many shots at all to finish them with this gun )

The hydra ( triple barrel shot gun and is very strong and extremely helpful when you being over run by majini as it is a triple barrel with wide range scatter shots )

Note: all three of these weapons do have to be unlocked first and fully upgraded ( you can't and don't have to upgrade the longbow )

After you have moved the giant boulder and sheva is with you and the real fight begins don't attack wesker until the red bulb on his chest can be seen.make sure you a rocket launcher to use and equip it and just avoid him until the bulb on his chest is visible, once it is quickly aim the launcher at the bulb and shoot and it will instantly take you to the final stage of the fight.