using code software to rename slug

As you can see in this image, Portfolio is a parent of Resources
http://prntscr.com/6z3apn

i would like to use Resources name using a ready portfolio in the theme and the url to be http://www.mydomain.com/resources ?

in order to do that i need to use code software, find names that is related and replace.

Can you suggest what is the easy code software to use?