How to manage Assets Picklists values?
1. Go to CRM Menu -> Support -> Assets Menu.
2. Click Customize button in the top right. and Click Assets Picklists value Menu.
3. First in Select module in module Field.
4. Select Picklist in your module.
5. Click + add Value button.
6. Open add item popup and Enter the information related to the Picklist.
7. Click Save button.