This won't be much of a tutorial but I'll give it a shot
Find your ban number on their forum
http://forums.multiplay.co.uk/complaints and keep an eye on it.
you're going to need to change 3 MAC addresses and your own ip address before you return
If you have a static IP address you're going to need a VPN or use ubertunnel on a VPS decicated server or whatever you can afford
the first 2 mac addresses correspond to network cards and can be easily changed. Formatting your hard drives will not change this
the HWID correspond to your C drive. This cannot be so easily changed because it's not a MAC it's a volume ID put there by the manufacture. Formatting the drive properly with windows vista or up if should change this and then installing a new windows on your C drive. If I am right then you can probably change your boot drive to different drive letter like D, and then format C: each time. Or skip MAC/VOLIDs completely by using linux which will show no HWIDs at all (except with wine)
After you thing you have changed everything, CHECK. Join a server with ACE that you can retrieve these details on to make sure they are changed, set up a server if you have to. Check the logs it's all there
Note that they DO log your mod menu items and MAY place your name on a watchlist which they will be notified when you are online.
Please report back here if any of this should not work for some reason
edit: Do not for any reason rejoin without changing all 4 of what was mentioned above, your efforts will only get the ones you have changed blacklisted and set you back.
remember you are changing your identity. if you really want to be safe then reinstall the game. it beats doing all this over and over if there is a way they are identifying you
