If you have any weapon up to and including True Scorpio, upon logging in after the update you’ll be prompted to Salvage your weapon. Salvaging the weapon will provide you with the new equivalent weapon, and in some cases will also return some of the upgrade materials and gold you spent.
You can find a detailed overview of updated items here.
Obsolete items will have a "Salvaging" section, in its details, showing the new replacement gear.
When obsolete items are in your Inventory, the "Manage Antiques" icon will appear (bottom right).
Clicking on this icon will open the "Manage Antiques" window.
You can salvage these items individually or all at once. The two buttons are marked below. Make sure you have enough free space.
Salvaged/Extracted items will be placed directly into your inventory.