To disassemble an item, you would need to approach a Disassemble Expert NPC where you can find in most of the towns in Midgard.
You would need to purchase a catalyst from the NPC to disassemble your unwanted equipment to get special materials required for refining and crafting. Different level of equipment require different grade of catalyst to disassemble them.
Note that disassembled items will permanently destroyed and cannot be restored.
To refine an equipment, you would need to approach the Disassemble Expert and click on the Refinement option. To refine equipment you would need either Oridecon (Weapons) or Ernium (Armor). Place the desired equipment into the Refinement slot and place the required material into the Material slot of the window.
Refining equipments with +1 or more has a chance to fail and degrade your equipment by a random amount, however equipment quality will not degrade lower than its original grade.
Failing an equipment refinement also has a chance to destroy the equipment. However you may choose to use Karnium to safeguard the item from degrading or being destroyed should the refinement fail.
The maximum level of refinement for all equipment is +10.
There is also a fee to refine each equipment.