Uhm . . . well, did you convert it to repaint the original? If so, just reverse the process. IE - incorporate the alpha channel back in and save as DXT3.
If you didn't convert it and just opened it and repainted, then you don't need to do anything. Just save as the same file type and everything, then pop it into a new texture folder.
If you don't know how to create a new texture setup, do this:
Name a folder texture.1 and put all your repainted stuff in it.
Open the aircraft.cfg using NOTEPAD and look for the first set of entries. They should be [fltsim.0] with a bunch of stuff under it. Copy that whole section, all the way down to the next set of brackets.
Scroll down until you see the section labled [General]. Place the cursor just above this section and paste in what you copied.
There are several things you MUST change for your repaint to work.
From the stock Baron 58:
Quote:[fltsim.0]
title=Beech Baron 58
sim=Beech_Baron_58
model=
panel=
sound=
texture=
kb_checklists=Beech_Baron_58_check
kb_reference=Beech_Baron_58_ref
atc_id=N058BE
ui_manufacturer=Beechcraft
ui_type="Baron 58"
ui_variation="White with blue and gold"
description="With the wonderful control harmony that is the hallmark of the Bonanza line, the Beech Baron 58 is considered a classic light twin. The Baron 58 is the spiffed-up version of a time-tested favorite, made more modern by its new Continental Special engines. The Baron combines the attractiveness of Beechcraft design with the reliability of twin engines, resulting in a gorgeous workhorse of an aircraft."
The [fltsim.0] must be changed to the next available number. If the last entry is a [fltsim.4] in that same file, then yours must be [fltsim.5].
The title= must change. This can be anything in the world you could possibly want it to be. This is just used by FS to distinguish between aircraft. It won't affect what you see in the sim.
Your texture set is in a folder called texture.1, so the texture= must now have a 1 after it: texture=1. If the name of the folder is texture.spleen, then the entry should read texture.spleen.
ui_manufacturer, ui_type, ui_variation. All of those CAN be changed, but I would recommend you change just the last one. Ui_variation is a the third tier in the Aircraft selection menu. This is how you will know what your aircraft is and where.
The description= CAN be changed, but you don't have to. It has nothing in it that affects how the aircraft works. And if this entry has statistics on aircraft performance, I would leave it alone, as it will look a little more professional.
Can't think of anything else, so if it doesn't work, come back and see me!
Travis