If you are wondering whether it would be possible to remove or modify a weapon attachment in Back 4 Blood (B4B), then the answer is obviously yes. All you need to do is find a weapon attachment in the game and press the indicated button as you approach it in order to equip it.
On the other hand, when it comes to removing an attachment, you will not be able to do it directly. The only way to remove the attachment used on your weapon is by finding another one and equipping it.
However, pay particular attention to the stats and the type of attachment for your weapon, as it will not be uncommon for you to be tempted by an attachment of better quality, but which will not be suitable for the type of weapon you are using as put a sniper rifle scope on an assault rifle.