Process for assembling and repositioning at least two timepieces by means of a repositionable hot melt adhesive, wherein said timepieces are held together in assembled position when said adhesive is at a temperature T A and can be repositioned in relation to one another when said adhesive is heated to a temperature Tc, comprising the steps of: a) preparing a solution of an adhesive comprising at least one formulation having the form of a mixture, on the one hand, of block copolymer chains comprising at least a first polymer block having a glass transition temperature Tg or a melting temperature Tf ranging between 40°C and 200°C, and at least a second polymer block comprising at least pendant diene units X and having a glass transition temperature Tg or a melting temperature Tf lower than a temperature T DA, and, on the other hand, of coupling molecules comprising at least two dienophile end groups Y, wherein said X units and said Y groups are arranged to be able to react with one another and to bond together by means of the Diels-Alder reaction at the temperature T DA and to be able to regenerate by means of the retro-Diels-Alder reaction at a temperature T RDA, where T A < T RDA ≤ T C, wherein temperature T DA ranges between 0°C and 100°C, preferably between 25°C and 70°C, and temperature T RDA ranges between 50°C and 200°C, preferably between 80°C and 150°C, and T DA is strictly lower than T RDA, and temperature T C is higher than the glass transition temperature Tg or the melting temperature Tf of the first polymer block, b) applying the solution of said adhesive to the timepieces to be assembled c) drying d) placing the timepieces at a temperature higher than or equal to the glass transition temperature Tg or the melting temperature Tf of the first polymer block to reposition the timepieces e) cooling to a temperature lower than or equal to the glass transition temperature Tg or the melting temperature Tf of the first polymer block, f) placing the timepieces at a temperature higher than or equal to temperature T DA and lower than T RDA to link the block copolymer chains to one another by means of the coupling molecules by the Diels-Alder reaction so that the adhesive is in the form of a three-dimensional network g) heating said timepieces to temperature T C to regenerate the mixture of block copolymer chains and of coupling molecules by means of the retro-Diels-Alder reaction h) repositioning the timepieces i) duplicating steps e) to f) j) if necessary, repeating steps g) to i) as many times as required to reposition the timepieces again. a) preparing a solution of an adhesive comprising at least one formulation having the form of a mixture, on the one hand, of block copolymer chains comprising at least a first polymer block having a glass transition temperature Tg or a melting temperature Tf ranging between 40°C and 200°C, and at least a second polymer block comprising at least pendant diene units X and having a glass transition temperature Tg or a melting temperature Tf lower than a temperature T DA, and, on the other hand, of coupling molecules comprising at least two dienophile end groups Y, wherein said X units and said Y groups are arranged to be able to react with one another and to bond together by means of the Diels-Alder reaction at the temperature T DA and to be able to regenerate by means of the retro-Diels-Alder reaction at a temperature T RDA, where T A < T RDA ≤ T C, wherein temperature T DA ranges between 0°C and 100°C, preferably between 25°C and 70°C, and temperature T RDA ranges between 50°C and 200°C, preferably between 80°C and 150°C, and T DA is strictly lower than T RDA, and temperature T C is higher than the glass transition temperature Tg or the melting temperature Tf of the first polymer block, b) applying the solution of said adhesive to the timepieces to be assembled c) drying d) placing the timepieces at a temperature higher than or equal to the glass transition temperature Tg or the melting temperature Tf of the first polymer block to reposition the timepieces e) cooling to a temperature lower than or equal to the glass transition temperature Tg or the melting temperature Tf of the first polymer block, f) placing the timepieces at a temperature higher than or equal to temperature T DA and lower than T RDA to link the block copolymer chains to one another by means of the coupling molecules by the Diels-Alder reaction so that the adhesive is in the form of a three-dimensional network g) heating said timepieces to temperature T C to regenerate the mixture of block copolymer chains and of coupling molecules by means of the retro-Diels-Alder reaction h) repositioning the timepieces i) duplicating steps e) to f) j) if necessary, repeating steps g) to i) as many times as required to reposition the timepieces again.