A way to change the quoting of property values from double-quotes to single-quotes:
Regular Expression is selected.
The Find pattern is set to: ="([^"]+)"
The Replace pattern is set to: ='$1'
Result is that all attrib values are set to using Apostrophe instead of quotes.
Fixing old html width properties.
Regular Expressions is selected.
The Find pattern is set to: width="([^"]+)"
The Replace pattern is set to: style="width:$1"
Result is f.x. that all width="100%" are set to style="width:100%".