I will show with an example how to do it.
let us supposed we need to change the following "Manager" sub-string into the class name
public interface IParticipantImageManager
in visual studio click on ctrl + shift + H
use any website to test your regular expression, personally I use regex101 to write the right expression and the replace it.to find the string
IParticipantImage(\w+)
and to replace the sting
IParticipantImage$1