You can't. I own heartgold and soulsilver and its not possible. You can trade with him though. The Pokemon you would have to trade would be a forretress for a level 30 beldum. Pineco evolves into forretress at level 30. and you can find pineco in trees all around both regions.
No, you don't battle Steven in HG/SS.
Go to Kanto and battle him at Mt. Moon, then you do a tag battle with him against Lance and Clair in the Dragons Den. THEN, battle him at the Pokemon League on Wednesdays and Sundays.
Steven is in Silph Co. in Saffron city
He does not appear anywhere else
You can use the ability Cut on Team Rocket. Since it is an HM, you can use it as a Pokemon move. All Pokemon moves can be used against Team Rocket in battle.
You battle your mom
you can bit i don't think you could battle
he goes to train his Pokemon in the Dragon cave behind the gym in Blackthorn. Find him there and he will join you in a double battle against Gym leader Claire and Champion Lance. After this battle you will be able to register Claire's phone number if you have won.
You can choose it between charmander Bulbasaur and Squirtle from Steven later in the game
he just trains with his trainer
They are ELITE FOUR so you go to the Indigo Plateu in Kanto after you beat them you battle Lance the Champion. Pokemon Battle Girls Battle Girl15
i saw it was possable to battle steven in heart gold his in the ruins of alpha but i went there but he is not there and i have got the starter of him ( i picked mudkip ) and now he is asking to trade a forretress for a beldum so good luck on you quest