Well, the answer to this question could be two options, cell wall and lysosomes.
The cell wall works in a way that this waste, can be anything that won't be useful to the cell, will be thrown out of the cell through the membrane, and this can happen because this cell membrane is made out of phospholipids, and they adjust themselves in a way that they can let this waste go through them to get out. This membrane also has transmembrane proteins that could help this process of exocytosis.
The second part, the lysosomes, work in a way that the cell waste goes inside this lysosome, and inside of it, there are multiple different kinds of enzymes that can turn this waste into little molecules that can be used by the cell instead of just throwing it away.