There are 2 very simple ways to edit / rebrand XCIPTV.
1. If you are using a PC, download a program called APK Easy Tool. Using this it is simple to decompile the apk you need. Go into the folders and find the .png and .jpg files. Simply change the originals to the new requirements, maing sure they are the same format and size. Then recompile.
2. Quite possibly a simpler option, for Android, download and install APK Editor Pro. Use this to decompile, then you can go into the images and again replace.
If you have any further queries, get back to me.