In Laeken there are several second hand shops. You can find your luck in JIPEX, Leyla, Spullenhulp or the bigger Kringwinkel where you can also deposit the stuff (clothes and other stuff) you do not want to keep anymore.

Second hand exchanges can also be done via social media dedicated to Laeken:

Laeken à donner

Coin occaz achats/ventes Laeken (et environs)