Well you need a debugger called softice, but be careful so you don't do something wrong with it as it can ruin your windows installation. However if you have no experience of debuggers or assembly, you should read some tutorials about it and try to do some basic trainers for any game with the help of a debugger. You won't need any hex editors. Just a mem searcher as well. You could always ask on gamehacking.com for more information.