Without cheating? You don't.
Lugia is in Navel Rock, which was an event location. It is currently inaccessible without using a cheating device, for the event has ended.
You can't.
you can't.
if you want to do it without cheating you'll need a ticket to get to navel rock from a Nintendo event otherwise you can't get lugia without hacking or cheating unfortunately.
No.
You can't catch Lugia in Pokemon Diamond. You can only get it through trading or cheating.
Can't
I don't think you can get lugia in platinum but for sure you can get Lugia in Pokemon heart gold, soul silver and when you got Lugia in one of those games trade it into you,r platinum game. hope it helps Brunoistheman ;D
You cannot. Dark Lugia is only available in Pokemon Colloseum.
there is no way srry <(-_-)>
you need an AR.
by trading it from Pokemon xd