Their Pokemon are actually pretty crappy. Have a good, high level Pokemon or cheat
beat mars in valley windworks
what?
easy... use the walk through walls cheat (but that invloves cheating)
Battle them.
u need to beat 7th gym leader
you need to have been to lake acuity and then the team galatic headquaters in veilstone city.
By defeating them in a Pokemon battle.
First you must defeat Commander Saturn at Lake Valor , Fly to Twinleaf Town and defeat Commander Mars at Lake Verity , Then you go to Mt.Cornet & the Team Galatic men will not be there.
You need to get past the Team Aqua grunts at Lilycove Town to advance on Pokemon Emerald. In order to do this, you first have to beat Team Aqua grunts at Lilycove Town.
Battle Them?
You need the HM Defog which is in the Safari Zone. Then you need to teach it to a flying-type Pokemon on your team (it is a flying type move). Keep this Pokemon in your party and you should be able to get past the grunts
beat the grunts