alterobj ITEM

This command will allow you to change the long and short descriptions of an item if you are skilled enough in the appropriate crafting skill. The difficulty of altering the item increases with the amount of enchantment on it. Failure will result in lowering the quality and increasing the weight.

This is considered an in-character action and it is highly inadvisable to change item material and describe an item you wouldn't normally see in that limb slot. For example:

Be wary about what you change. Some items have their descriptions edged in their special abilities, so these should be changed with special care.