Software :: How To Convert Files To UTF-8

I have sites written in Win-1250 alias cp150. I need to convert all files to UTF-8. I know about iconv but I found problem with this tool. When I tried to convert I had to make a copy of the original file. But I have many files in (sub)folders. So If I would want to use iconv instead, I would need to convert all files from *.php to *.tmp and than copy or rename back to *.php. This looks too difficult.ther way how to do it, something intelligent and simple