A petition executed by at least fifty-one percent (51%) of the qualified electors residing within the portion of the county proposed to be annexed shall be filed with the county commissioners of the county in which such portion is located. Such petition shall set forth the facts showing the existence of the conditions described in Section 1 [4-33-1 N.M. Stat. Ann.] hereof and shall accurately set out the boundaries of the portion of the county proposed to be annexed.