How is it done? I recently started playing again and have no idea.

on the organize items page (linked at the top of the wardrobe) you can check off items you want to remove from your wardrobe and click "update items."

go to your wardrobe, the tab at the top that says 'organise items' you can filter the items by id or timeline etc, and use the search function. then it will show the item and you can tick the box at the side it goes to your inventory. I found out that you can click on items and that ticks the box as well.
Like the name :0)

Oh ok! Thank you :)

if you only want to remove one item and you know its Item Name, you can use Account Search. You will get the opportunity to click 'Remove One'