Confused about Livery Tail number and Definition file

Hi,

I got confused here - as title already said - about this definition file.

From reading the introduction document it seems that everything is based on a new livery

associated with only 1 definition file.

What I am trying to accomplish is the PMDG 777 house color livery to have 2 definition files:

one which is the PMDG default (don't want to change that)

two is mine (777ARO definition file)

and be able to select it from the aircraft menu

What I did with the NGX is creating the.ini file and then in the details of the aircraft selection I changed the (frame) number. This way I could select the 737 NGX housecolor with my profile.

Now I read that this is not the way to do it, but nowhere in the ops center I see the possiblity

to add a new definition file to an existing airframe nor how to select it.

Any suggestions on how to do this ?

(I am reading this at work so don't have the tool in front of me to play with, just the document. So apologies if I missed the obvious...)

kind regards

Dieter