Well as I said earlyer when your IP changes just log to your original admin/gm account it'll update.
MACs are even easier to change than IPs. (Google: TMAC V5 R3 / Technitium TMAC)
I don't agree to this :/:
I thought its easy to fake a mac than changing it as to IPs you can change/fake it much easier than mac
Not really. The internet communication is based on IP, not on MAC addresses. Sure, you can spoof a packet's source IP address, but you're also going to fail TCP handshake.
It's not as easy as just changing a registry entry and *poofs* your IP changes. Both the source and remote host need to know each other's IP address in order to communicate.
Which is why IP spoofing are only mostly used in DoS attacks.