Changing "services" to "locations"

I was impressed with how close I was able to get to want I wanted with "out of the box" the functionality of Appointments+. Currently all I need to change is some text. I need to change "Please select a service:" to "Please select a location:" for starters.

I am not a plugin developer so this is probably an easy fix. I go to Plugins->Edit Plugin and search the source for "Please select a service:", then change "service" to "location". But when I click save I get "Service Temporarily Unavailable The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later."

How can I change service to location in the user viewable text? (I don't care if everything is still called "services" on the back end)

Thanks in advance.