you cant. you have to trade them from Pokemon emraled.
yes its easy
Yes you do.
you can use cheats or have a regigigas from the 11th movie
no \ i caught over a hundred already!
If you want Regirock, Regice, and Registeel on Diamond, you'll need to trade from Platinum, or migrate from Ruby, Sapphire, or Emerald.
try the caves where you find the regies also there is a tower by dewford where you can find raquaza
Unfortunately, you must migrate the regies from ruby or sapphire. You cannot catch them in pearl/diamond.
no you need to have the three regies in your party to make regigigas appear
buy the Pokemon platinum book
you must trade them
The 151st Pokemon is Mew and is unobtainable in Pokemon Platinum.
You can't find it at Pokemon Pearl you have to Transfer it from the GBA Games Ruby/Sapphire/Emerald via Pal Park