It doesn't. It is already fully evolved.
if u have a female snorunt evolve it with a dawn stone
Male Kirlia---->Gallade Female snorunt ------>Froslass
you evolve a girl snorunt into froslass
Dawn stone- Male Kirlia evolves into Gallade Female Snorunt evolves into Froslass
SoRrY, bUt ThErE iS nO fRoSsLaSs In PoKeMoN dIaMoNd.... but there could be, i may be wrong. but there are many websites you can go to to find out.
Unfortunately, you can't get a Froslass in Emerald. Froslass wasn't introduced until the Generation IV games (Diamond, Pearl, and Platinum). You can get Snorunt (in Shoal Cave during low tide), but you won't be able to evolve female Snorunt into Froslass until you move it to a later game. If you do, you can evolve it using a Dawn Stone.
Evolve a female Snorunt with a dawn stone.
Froslass doesn't exist in the third generation games, so you can't evolve Snorunt into that.
Two Pokemon can evolve if exposed to the Dawn Stone. A Snorunt will evolve into a Froslass, and a Kiralia will evolve into a Gallade.
You must evolve Snorunt, which you get in the PokeWalker.
glalie doesnt evolve into froslass. snorunt evolves into froslass if you use a dawn stone and it has to be a female from bob the builder Yeah, you can't evolve Glalie to Froslass. Check out http://bulbapedia.bulbagarden.net/wiki/Froslass_(Pokemon) It doesn't say anything about Glalie evolving into Froslass. You need to evolve a female Snorunt with a Dawn Stone to get Froslass. (Yeah, I mean, why would a male be such an elegant feminine Froslass?)
you evolve a female snorunt with a dawn stone and then you have a froslass P.S Hope i help