Guages and .XML files

I love downloading new planes and helicopters, i think there the best! 
You might have noticed when you download a plane, that in the guages folder there might be another RAR file. Once you extract this there are image files and .XML files. ???
All i want to know is where do you put these.
Plese, can anyone help

You might have noticed when you download a plane, that in the guages folder there might be another RAR file. Once you extract this there are image files and .XML files. ???
All i want to know is where do you put these.

Plese, can anyone help