How do you play with that "extremely aggressive" players?
That depends. Are we discussing aggrotards or decent LAGs here? The first thing is to realize that this kind of play increases variance. If you're not comfortable with that, then it's best to seek a new game.
If this is a garden variety aggrotard, simply find a playable hand. Even a second or third button could be good against some
bluff-monkey. You just let him bet it for you and hope you're good, and he doesn't bink before the river. I have a reg where I play whose strategy is to buy for a half stack, and raise AI. He's hoping to double up and then play it tight. It doesn't work when I'm in there. I've called this guy pretty light and stacked him more than a few times. He never learns.
If it's a good LAG (and those are few and far between at u-stakes on-line) you need to get a line on his range and play a somewhat tighter range, which means light 3 and 4 betting. The problem with nitting it up against a good LAG is that he will rob, rob, rob most of the time, but when you finally find a hand, he'll know where you're at and he'll suddenly discover what the "Fold" button does.
You definitely want to be in position against either aggrotards or good LAGs. You also need to understand that you could lose a whole stack. Even the bluff-monkey or LAG can pick up a pair of aces.