Open up the aircraft.cfg file, copy the one from the houselivery and change it so it works for whatever livery you want to install. For example:
[fltsim.0]
title=Embraer 195 house
sim=195
model=
panel=
sound=
texture=house
kb_checklists=
description=
ui_manufacturer=Embraer
ui_typerole= Regional Jet
ui_createdby=FeelThere
ui_type=Embraer 195
ui_variation=Embraer 195 Rollout
atc_heavy=0
atc_id=PP-XMJ
atc_airline=Embraer
atc_flight_number=HOUSE
[fltsim.1]
title=Embraer 195 LOT
sim=195
model=
panel=
sound=
texture=LOT
kb_checklists=
description=
ui_manufacturer=Embraer
ui_typerole= Regional Jet
ui_createdby=FeelThere
ui_type=Embraer 195
ui_variation=Embraer 195 LOT
atc_heavy=0
atc_id=LOT
atc_airline=LOT
atc_flight_number=LOT