A trainer ain't really needed. If you want to make it easier, make a mod. Select mods from the menu, click on the + icon to create one. Then click the pencil icon to modify the mod. You can set a lot of options there. Just read carefully which values have to be set on each option.
But I bet you all can figure it out in no time. Good luck
Will the game let you score Achievements with mods?
{EDIT}
Apparently not, according to this thread. Link
[Edited by predcon, 7/6/2011 5:34:54 PM]