Try:
The slashes need to be escaped, hence "\/". Then a space, "\s" and "(.*?)" is capture any text but not the space before the closing doubleslashes.
With the replacement:
Note, for the search, I would probably use:
Code:
\/\/\s*(.*?)\s*\/\/
That covers any amount of whitespace around the text. With either, you need to be careful in case there missing doubleslashes.