There's no easy way to do it in Studio, other than using the Search button to manually change them one by one. However there is also a trick you can do, which although introduces risk, if you are careful it can save a lot of time.
Export the process as an XML file. Open the file in Notepad do your Find/Replace, but be very careful not to accidently accidentally disrupt the XML structure. The re-import the file, over writing the original. If it won't import then the XML has been compromised somehow.
