1. Clean the surface: Clean the surface with warm water and soap to ensure it is dry.

　　2. Prepare the glue: select the appropriate glue and prepare according to the instructions.

　　3. Fill the cracks: use a small brush or stick to fill the cracks with glue, and ensure that all gaps are filled.

　　4. Compaction of materials: put the two sides of the crack together, and gently compact them with hands or clips to ensure that the glue is fully contacted.

　　5. Wait for drying: according to the instructions of the glue, wait for enough time to make it fully dry.

　　6. Sandpaper grinding: Use sandpaper or grinder to smooth the repaired part and keep it consistent with the surrounding surface.

　　The above is the best way to repair the glue, but if you are not sure about your repair ability, please seek professional help.

　　Just stick it back with glue.