1. you need to make the 256K bios into 512K using XBtool but I have a feeling that Xbtool only supports 4981 and earlier. Also what version is your Xbox. don't flash this bios if you have a 1.6
2. To guide you through this step by step would take a lot of space. basically you will have to connect to the box via FTP and delete the apps, emulators etc that you dont want. If you know how to put this on why did you not just ask for the chip to be installed but nothing else, it would have saved some messing.