Hi, it’s actually not recommended to replace CSS class names and script variables as they might be associated with various styling and functionalities. But if you must rename them then there is a way which need a bit of coding skill.
For example: If you want to replace css class name “wp-navbar” to something like “xyz-navbar”, then you’ll need to add following replacement in “replace in html”:
wp-navbar ==> xyz-navbar
Then copy the css code from for wp-navbar from respective css file, replace occurrences of “wp-navbar” with “xyz-navbar”, and add it in “Internal CSS” option in HMWP Source Code tab.