1. First, clearly indicate the length of your paper in your cover letter and explain why you have exceeded the word limit. For example, you can point out that you think this paper needs more details and background information, or you think that additional data and experimental results are very important for your research.
2. You can provide some concrete examples, such as deleting some paragraphs or streamlining some sentences, but these deletions and streamlining may affect the quality and integrity of the paper.
You can emphasize your research achievements and innovations, and point out that these need more space to be fully displayed. You can point out that your paper may be more challenging and complicated than other papers in some aspects, so you need more words to describe it.
Finally, you can ask the editorial department to consider your requirements and give you some feedback and suggestions so that you can further streamline your paper. You can ask the editorial department to indicate which parts or contents can be deleted or simplified, so that you can reach the word limit.
No matter how you explain it, you should be honest and modest, and provide as many explanations and examples as possible. If you can convince the editorial department, they may consider your request and accept your paper.