The utility model patent I applied for has been authorized and issued with a certificate for three years. I want to modify the contents of the patent now. How?

If there are dependent claims in the claims for protecting the new technology, it is not necessary to remedy, and the dependent claims can be directly used for protection. Of course, you can also declare this patent invalid and narrow the scope of protection of independent claims, which is useful in litigation.

As for the remedial measures, there should be no more. It is certainly not novel to apply again.