Replace URL in Android App .apk file

I have three apps ( .apk ). They are players for IPTV that have hardcoded line URLs somewhere in the code, but I cannot find them. I would need someone to find the code responsible for the line and show me where it is and how to see it, or even better, amend it, compile it and send it back to me. Easy job. Please do not bid if you cannot do it in the next 30 minutes.