[Asterisk-Users] changing configuration file

[amna saleem]

hi!
I am a beginner at Asterisk and Linux,I am trying to place a call
using IAX ,but don`t really know how to chaneg the configuration
file.I open the /etc/asterisks directory ,then open the iax.conf file
from there but can`t edit it .Can anyone please help me reagarding
this issue.How can a configuration file be changed or edited???? Does
the same apply if I want to change the dial plan as well?

Amna