How to Unlearn a Profession

While Primary Professions can be abandoned anytime you choose to pick a different option, the Secondary Professions of Archaeology, Cooking, and Fishing cannot be abandoned or reset.

Modern WoW

To abandon a primary profession: 

1. Open your Spellbook (default key for this action is "P")
2. Click on the "Professions" pane
3. Click the round red icon next to you profession skill bar

A confirmation window will appear.

WoW Classic

To abandon a primary profession: 

1. Open the character pane
2. Click on the Skills tab at the bottom
3. Click on the profession
4. Click on the "Unlearn this profession" button

A confirmation window will appear.