[Bungleau]

All available class changes will be shown to you in each guild you belong to. As a priest, you start out in the temple, and only have the choices you mentioned.

There is an alternative, however. You can start on the paladin quest, which makes you eligible to join the warrior guild. You can then cancel the paladin quest (by clicking on it again) and from the warrior guild, take the ranger quest. This is known as the guild-hopping trick; the only downside is the money you paid for the original class promotion. It's gone, and when you want to become a paladin later, you'll have to pay again.