Extract the folder Texture.FAB into your FSX installation folder/SimObjects/Airplanes/PMDG 777F.
Add the following lines to aircraft.cfg:

[fltsim.x]
title=PMDG 777-200LR UIA (Fictional)
sim=B777-200LR
model=
panel=
sound=
texture=LAA
atc_airline=UIA
atc_id=UR-LAA
atc_flight_number=PS094
atc_heavy=1
atc_model=777-200LR
atc_parking_types=GATE,RAMP
atc_type=BOEING
ui_createdby=PMDG
ui_manufacturer=Boeing
ui_type=777-200LRX
ui_typerole=777-200LRX
ui_variation=Ukraine International Airlines - UIA (Fictional)
airline_name=Ukraine International Airlines - UIA
description=Boeing 777F powered by GE90 engines v 1.0\nPMDG Simulations\nwww.precisionmanuals.com \n\nProduced under license from Boeing Management Company.\n\nBoeing 777, 777-200LR, 777-200LR & Boeing are among the trademarks owned by Boeing.
visual_damage=0
PMDG_Version=1 // **DO NOT EDIT THIS LINE - PMDG OPERATIONS CENTER USE ONLY**



Do NOT forget to replace the "x" in [fltsim.x] with an appropriate number.
Do NOT forget to save the aircraft.cfg file before you exit.
Enjoy!