Go to :
/Developer/Library/Xcode/Templates/File Templates
or if you're using the newer self contained Xcode.app
,
/Applications/Xcode.app/Contents/Developer/Library/Xcode/Templates/File Templates
To avoid the templates from being clobbered by Xcode updates, make a copy of the template that you want to edit and move it to your home library folder–
~/Library/Application Support/Developer/Shared/Xcode/File Templates
If - let's say - it's the Objective-C class template you want to change then, go to the following subdirectory :
/Cocoa/Objective-C class.xctemplate
Open :
NSObject/___FILEBASENAME___.h
NSObject/___FILEBASENAME___.m
And edit them.
Hint : You'll have to tweak as many template files as you need (e.g. if you need your copyright header to be valid for NSDocument subclasses, then make sure you edit those files too... ;-))
An example (of what my ___FILEBASENAME___
files look like) :
/******************************************************
| ___PROJECTNAME___
|******************************************************
| File : ___FILENAME___
|
| Created on ___DATE___
| By Ioannis Zafeiropoulos (a.k.a. Dr.Kameleon)
|*********************************************************************
| Copyright (c) ___YEAR___ InSili.co.uk. All rights reserved.
|*********************************************************************/