To edit or change or update the tax details like Tax Name or Tax % in inventory, follow the steps given:
Step 1:
Select the Inventory module and then select the Create Items under the Item Details menu.
(Inventory-->Item Details-->Create Items)
Step 2:
Select the Inventory Tax Master option. Against the respective tax name, click on the Edit icon
given.
Step 3:
Update the changes accordingly and click on the arrow mark to save the details.