I need help how to reverse-engineer EXE files - assembly

[UndeadHalfOrc]

I need help how to reverse-engineer EXE files - assembly debugging, de-compiler, that kind of tool - what can you expert recommend me?

The reason is that I'm desperate to find the offset in the Heroes 2 exe file where is buried the value 10, (0x0A) which is the multiplier for the damage of spells, FireBall, FireBlast, and Cold Ring. I want to change it to 13 like I did with Heroes 3.

So, what tools do you recommend?

Thanks.

[Nomad]

If you want to simply change one byte, then try hex editos like HView or WinHex.
If you're going to analyze the code, use IDA 5.5 + HexRays plugin or Microsoft Visual Studio (C++).

[Kristo]

When reading the decompiled code, a good place to start would be the data structures you already know something about. If you can find the declaration for the creature stat tables, for example, you can search the code for where those variables are referenced.