- Go to the Setup Page (⚙️) on the bottom left of the page just above your profile picture.
- Under Customization, select Modules and Fields.
- Click on the module you would like to edit, select Standard.
Navigate to the option you would like to edit the pick list on, click the 3 dots on the right hand side of the field and select Edit Properties.
Use the plus sign (+) to add and the minus sign (-) to add and/or remove options from your pick list.
Click done, then click on save and close.
For a detailed walk-through, please see the following video: