Look for three files similar to these: Horn.bin, Horn Sound.proxybin, and Horn Sound.proxyxml. Copy all three files and rename them. (Ex- Horn 2.bin, etc.). Open the Horn.bin with .serz and then edit it with notepad. Locate a line of text which consists of "Horn Sound" and rename it to "Horn Sound 2." Now edit your repaint's engine.bin by locating the "Horn" inside. Do a quick search by typing in "horn" and find the line of text that refers to the horn.bin file. Change to "Horn 2"
It sounds really confusing, so if you need me to explain further then I certainly can. Here are some examples from the P42DC horn files:
P42DC Horn Sound 201.bin, P42DC Horn 201.proxybin, and P42DC Horn.proxyxml are my new copied files. How to edit the files:
-"P42DC Horn Sound 201.bin" had this line of text edited: <ProxyName d:type="cDeltaString">RSC\P42Pack01\Audio\RailVehicles\Diesel\P42DC\Cab\P42DC_Horn 201</ProxyName>
-"P42DC Horn.proxyxml" has been edited to read the new horn.
-The line of text that needs to be edited in the repaint's engine.bin should look like this: <BlueprintID d:type="cDeltaString">Audio\RailVehicles\Diesel\P42DC\Cab\P42DC Horn Sound 201.xml</BlueprintID>
