1. Use a scraper or other tools to completely remove the old opening glue. If necessary, the surface can be cleaned with detergent and rag.

2. aim the glue gun at the gap or interface to be filled, and start to extrude the opening glue. If necessary, you can use a scraper to shape the glue.

3. Before the opening glue is dried, use a cleaner and a rag to clean up the excess glue.

4. according to the instructions of the opening glue, wait for it to dry and cure.