Hi,
why?
You will find all named object with this xxxxx$0$
yyyyy$1$
..
prefix. Layer Blocks dimstyles styles and more.
They was content in another file, linked by XREF comand and someone use bind option to import this external stuff to your file.
1. If the are all from the same file, or all have the same length of reference name,
you can do it by using the RENAME dialog.
Old: oldrefname$0$*
New: oldrefname*
If you want to remove $0$ only, this is a quick ootb way.
(You can find tools for "find&replace" for named objects, it isn't a native feature)