You can do a flush header, for a 36" door the header would be 41" long and the same size as you have now .
You would have to put support under the rafters above. cut 41" out of the top plates and put the new header right under the rafters with a new king and jack stud on the left and just a filler block on top of the jack on the right.
You would have to put support under the rafters above. cut 41" out of the top plates and put the new header right under the rafters with a new king and jack stud on the left and just a filler block on top of the jack on the right.