The topic of how to open Playmobil boxes without damaging them has long been discussed but he box for the 4221 ambulance has a new way of opening which means that it can be easily open without damage and reused for secure storing of the item.
At each of the bottom rear corners of the unopened box is a quarter circle marked to be cut, while at the front of the box is a half circle similarly marked. I cut the sections out by running round them lightly with a small modelling knife. The pieces can then be pulled away (they are held in place by blobs of glue). The box is still held closed by a couple of blobs of glue at the front and maybe one each side (I can't remember exactly and it is now upstairs in the loft) so insert a knife between the box lid and the box body and slide it round to cut through the glue. The lid can then be lifted up to open the box. In the case of the ambulance, to store it in the box after putting it together, it needs to have one door mirror removed so it can be laid on one side as when on its wheels, even with the roof removed it is slightly too tall.
This method of opening means items can be store in their box quite safely and seems better to me than the other reusable method as used, for example, on the police vans (3160 and 3166) where a central strip is removed from the end of the box and there is then a tab on one box flap which tucks into a slot in the other flap to close the box back up.