Hi guys, I just got 1 simple question ( Topic says all )

If it's in Emerald just move tutor it on it through the Battle Frontier.

If not, get a male Medicham that has it, breed it with Lopunny.
Take a male whatever the heck a Lopunny pre-evo is called and breed it with Weavile.

Medicham gets Ice Punch via Heart Scales if I recall correctly.

there's no way to get Ice Punch onto a Weavile that doesn't have it.

the quick way to do it is to breed using Smeargle.