That is correct (at least in v7. I don’t use v8 so, I don 't know about v8).
However, some ways to change them in Bulk:
#1) Edit the File (text edit)
#2) Use a Python code to do Search and Replace (I’ve posted code to do that, search for it) or, write your own code
#3) Use the Python Console tool in the PCB Editor and grab the elements from my posted code or write your own
The Simplest way is #1 shown in Video below and Python Code #2 shown in video
Amusing myself… If inspired to create Python code, you can take it a step further and make it into a real Stand-Alone-App… see Video #3
#1 Video
#2 Video
#3 Video