Re: How to modify a function of a package

[Nikolay Kudryavtsev]

Since everyone gave you only the more advanced answers, here's also the 
simple ones:

1. You do (require 'package) before redefining a function in it. Won't 
always work, a package may do something really sneaky with it's 
functions, but should suffice for most cases.

2. If you use use-package, put your function redefinition into the 
:config form and that's it.