Your response to an Office action must specify the problem to the satisfaction of the examining attorney. Otherwise, you risk having your trademark application rejected. Because of this, and because the difficulties with your application may be hard to resolve, you may want to ask the advice of a trademark attorney before replying to an Office action.
In most cases, the USPTO must get your response within 6 months of the mailing date on the Office action, except if the letter defines a different deadline. The deadline is necessary: It cannot be increased and, if you miss the deadline, your trademark application will be rejected.
The USPTO favors getting answers to Office actions online by their Trademark Electronic Application System (TEAS), though you can also submit a reply by fax or mail. The USPTO website has information on how to submit a response.