The invention provides a method wherein a first unit (10) is provided having a field of grip elements (12), and a second unit (20) provided with retention means (22) suitable for co-operating with the grip elements (12) of the first unit (10) in order to provide a self-gripping fastening. The first and second units are put into contact in such a manner that the grip elements (12) of the first unit and the retention means (22) of the second unit provide a self-gripping fastening (F). A treatment zone of the self-gripping fastening is treated in order to deform the grip elements (12) of the first unit (10) and/or the retention means (22) of the second unit (20), whereby the first and second units (10, 20) are permanently secured to each other, thereby forming an assembled structure.
