We removed the handles and the three front plates. At the hardware store, they already cut the three pieces of plywood to the right size.
My brother in law helped me (again) with putting the right size holes in place of where the drawer fits the front and made the two holes.
He used the original fronts as the model for drilling and sawing the holes. He advised me not to make the groove where the bottom of the drawer fits in. Rather, we cut a small strip of the front of the drawer, put the front together and screwed four small corner profiles on the bottom so it stays perfectly fixed.
On the side we added an extra plywood shelf that was the right size for the laundry basket and the IKEA HÅLLBAR bin.