Priest

1. In the game, open the Book of Talents. Every character has one in the bags, innkeepers sell new ones.
2. Pick a spec, then Load a build from a site link on its page.
3. Paste the link into the box with Ctrl + V, then press Accept.
4. The talents load into the chosen spec by themselves.

The build replaces the talents of the chosen spec, for free. To keep your current talents, load the build into another spec: no need to switch to it first.