Hello Spiros,
hopefuly i’ve understood the question – does this give you what you require?:
With “Use Regualr Expressions ticked” and under “Advanced” – “^ and $ can Match beginning and End of the selection”
Find:^([^<i>]*)</i>
Replace with:\1
“Replace All” until no more instances found).
then
Find:(</i>[^</i>]*)</i>
Replace with:\1
(again, “Replace All” until no more instances found).