A. In full view of the overall purport of the pleadings as to Gap evidence Nos. 1 through 3 and Eul evidence Nos. 1-1-1, the plaintiff and Dong E (Death on March 5, 2020) concluded a mortgage contract on the size of 992 square meters for Pyeongtaek-si D forest (2/3 of the real estate register No. 1/3 E/E) on October 16, 2019. However, due to the error in the legal office that performed the registration of the establishment of a neighboring real estate by proxy, the establishment of a mortgage contract on the above real estate was completed only for the "Seoul-Gu No. 2 and 3 E/E" rather than for the "Seoul-Gu No. 2 and 3 E shares" as of October 16, 2019 as of the same day, and the defendants, the deceased's heir, respectively, are recognized.

B. According to the facts of the above recognition, the Defendants are obligated to implement the registration procedure for the change of collateral security with the purport of changing the “establishment of the entire E share No. 3 E” in the column for the purpose of registration of the establishment of collateral security, which was completed on October 16, 2019 by the registration of the Suwon District Court of Suwon-gu with respect to the size of 992 square meters of Pyeongtaek-si D forest land, and the establishment of the entire E share No. 3, which was completed on the same day contract as of October 16, 2019.

2. In conclusion, the plaintiff's claim against the defendants is justified and it is so decided as per Disposition.