Instructions
Find a Protector item. At least one Protector can be found in every game from "Pokemon Diamond" and "Pokemon Pearl" onward. It can be found on Route 228 in the "Diamond," "Pearl" and "Platinum" versions. A second Protector can be obtained on Iron Island. A Protector is waiting in Mt. Mortar in both "Pokemon HeartGold" and "Pokemon SoulSilver." A pair of Protector items are in "Pokemon White" and "Pokemon Black." Check along Routes 11 and 13 to collect the two Protectors.
Give the Protector to a Rhyhorn to hold. Select the Rhyhorn from the Pokemon in your party of six, and choose the "Give" option. Flip through your item list and choose the Protector.
Trade Rhyhorn to another Nintendo DS game while it is holding the Protector, and it will evolve into Rhyperior right away. Send Rhyperior back so you can enjoy the mighty beast on your version of "Pokemon."