In Odoo Manufacturing App, you can Unbuild products. Two use cases can be managed: (1) you can unbuild products you have built yourself or (2) you can unbuild products you have received.
Let's take the first case, you are manufacturing products yourself. If one of your product presents some defect, you might want to unbuild it instead of scrapping it completely, allowing you to reuse some components of the product.
In the second case, you are buying products for the sole purpose of unbuilding them and recycling them.
While in the Manufacturing App, under the Operations tab you will find the menu Unbuild Orders.
When creating a new one, you can either select a MO if you are unbuilding something you manufactured or only select a product if you are unbuilding something you received.
When you are done, just click unbuild and the process will be over.
If you unbuild a product that you manufactured before, you will get the components from the MO back in stock.
If you unbuild a product you bought, you will get the components from the BoM back in stock.