.. so im not a thief. understand that, i just changed some things, that i downloaded legaly.. which is complelty different.
Just read the license agreement and you will see that it is not allowed to "change some things".
And I am sure you cannot download a full copy of TombRaider legally where you can "change some things" to make it a full game. The demo version is smaller and does not contain all levels. You probably searched for a warez version.
All these excuses dont make it legally or make you a saint. It is wrong, period.