Calm down, people who can help aren't always awake and/or around to answer questions...
You want to look in \Vehicles\MB_O530_Facelift\Model\. Inside you will see:
As you can see there are quite a few of these files because there are a lot of different variants of the bus.
If you look in one of the passengercabin files, you'll see something like this (this is from the 2-door Citaro):
Code:
###################################
[entry]
0
[entry]
1
{noticketsale}
[entry]
2
{withbutton}
[entry]
3
{withbutton}
[exit]
2
[exit]
3
###################################
You want to remove the definitions of entrances with an index higher than 1, so you get this:
Code:
###################################
[entry]
0
[entry]
1
{noticketsale}
[exit]
2
[exit]
3
###################################
Obviously if you do this for a bus with more doors, you'll have more exits to leave in place.