changing UPPER to lowercase keywords in Bridge or Lightroom

Hello,

Apologies if this has been covered, but I'm new and somewhat on a deadline.

I have a batch of about 1,000 images for work that have been tagged with a keyword and then an ID number. They are currently in uppercase, but I need them in lowercase. The keyword and the ID number are also in quotations (to qualify them as a single keyword together).

Example:

current keyword, including quotation marks:

"BLSSI.COM_PERSON_ID=964820"

ideal:

"blssi.com_person_id=964820"

If it weren't for the quotation marks, I think I could figure out how to batch-rename them, but since they are in quotation marks, it makes for every file (which all have different numbers at the end) being its own, separate keyword. Does that make sense? I'm looking for a way to just change the letters within the quotation marks to lower case instead of upper case.

Is there any hope for me? I can also work in Lightroom, but I'm not savvy with scripts or coding. I'm on a Mac with Bridge 2017 and Lightroom CC (I can upgrade if need be, too).

thanks

Laura