Dear Sir/Madam,
I was born in Ponta del Gada in the Azores Islands in 1989. I was born to Portuguese parents and was adopted by American parents. I have my original Portuguese passport which was issued to me as an infant along with my Portuguese birth certificate. I also have my legal US adoption papers. Presently, I have an American Passport. I am now living in Almaty, Kazakhstan as my parents are employed here and I am their dependent.
Dear Sir/Madam,

I would like to know how to re-activate my Portuguese passport. It is my understanding that Portugal will allow dual citizenship, but, If necessary, I would relinquish my U.S. one.

I am not sure how to go about doing this and am hoping you can advise me. If there are forms to be completed please send them care of this email address. Please advise of any related fees.

Sincerely,
Dylan >Personal Info Removed<

Check this out:
https://www.askmehelpdesk.com/visas-passports/portuguese-passport-information-read-me-28679.html

Thank you Rick for your information. However, it refers to those who were born in India and does not really address my situation. I was born in the Azores to Portuguese parents and have my original Portuguese passport and Portuguese birth certificate which were issued to me at birth in 1989. Because of a 'closed' adoption the identity of my birth parents was never disclosed so I have no way to confirm their nationality and I cannot locate them. I am now 21 and would like to have a Portuguese passport under my birth name. How can I get my expired passport activated again? Any further info would be helpful or the name and contact info of a solicitor/legal firm in Portugal that can handle this. Thank you for your efforts.

See the last part in the link that I posted: Especially the first one.

* The reader must consult and refer to the nearest Portuguese Consulate and ask for detailed and up to date information before proceeding.
* It would be advised to search for professional help as well (lawyer or solicitor).
* Please note that Portugal allows dual nationality but not all countries allow and you should be aware of this before applying.