First get the SGA KDC-10-30CF package ( sk1kdc10.zip ) in this package are already 3 Royal Netherland Airforce (K)DC-10-30
Copy the 2 texture maps you just have downloaded into the same map in your FLIGHTSIMULATOR9/AIRCRAFT/SGA KDC-10-30 map.
In this map is also an aircraft.cfg file, open it with your notepad and insert the text bellow under the last [fltsim]
and gife the x in [fltsim.X] the next number

[fltsim.x]
title=SGA KDC-10-30CF N1858U / T255
sim=SGA1030
model=30
panel=
sound=
texture=N1858u-1989
kb_checklists=DC10CL
kb_reference=
ui_manufacturer=McDonnell Douglas
ui_type=DC-10-30
ui_variation=46987-255/N1858U United airlines 1989
visual_damage=0
description=Model by SGA,This N1858U from United airlines came to the Netherlands on 25 October 2004 for the Royal Netherlands Airforce to rebuilt as DC-10 T-255
atc_heavy=1
atc_id=N1858U
atc_airline=Air Force
atc_flight_number=255

[fltsim.x]
title=SGA KDC-10-30CF N1858U/T255
sim=SGA1030
model=30
panel=
sound=
texture=N1858u-2004
kb_checklists=DC10CL
kb_reference=
ui_manufacturer=McDonnell Douglas
ui_type=DC-10-30
ui_variation=46987-255/T-255 KLU 2004
visual_damage=0
description=Model by SGA,This T-255/N1858U from United airlines came to the Netherlands on 25 October 2004 for the Royal Netherlands Airforce,the arrival was in this United airlines colourscheme.
atc_heavy=1
atc_id=N1858U
atc_airline=Air Force
atc_flight_number=255


Greetings Harold Pot
http://members.home.nl/virtual-twenthe