I'd think you'd have to do it manually. If in the source code, you use ==, I guess you could use the find and replace and adding = by the amount you need to downgrade all of them. But I don't think there is a way to do that.

Assuming no edge cases with strange syntax, I think the following regex would do:

Regex:

^[=]{2,4}.+[=]{2,4}$

Replace with:

=$1=

Sorry, this is the corrected regex, actually tested this time...

^([=]{1,5}[^=].*[=]{1,5})$