How you respond depends entirely on the issue that was raised by your examiner. Some office actions require only minor corrections, which can be addressed through a straightforward amendment or a brief written response. Others; particularly substantive issues such as likelihood of confusion or descriptiveness; require a formal written response with legal arguments, and sometimes supporting evidence.
Responses are submitted through the IP office's official portal within the deadline specified in the office action. Working with a trademark attorney to draft the response is advisable for substantive issues; the quality of the arguments and evidence submitted can determine the outcome.
Start with a free assessment of your office action with Trama.