Because RIO Inventory is a Managed Package, you can’t just edit the field labels like normal fields, but you can still rename the field labels if you follow these steps.
1. Go to Setup > Translation Workbench > Override
2. Select the following fields in the filter criteria:
1. Package: RIO ReadyMade Inventory
2. Setup Component: Custom Field
3. Object: The Object with the field label you want to change. In this case, we chose the Warehouse Inventory Object.
4. Aspect: Field Label
3. Find the field you want to rename. Double click on the Field Label Override column next to the field.
– Type in the new label name you want.
– Click Save at the top.
After completing these steps, that field will now use your custom label in the Salesforce Page Layouts.
Note: This only shows on the page layouts. The custom Visualforce Pages will still use our standard terminology.