Open the save games editor, now click open from the file open in the top right corner. Find and load the .das file of your game. It is a fairly small, around 200KB file. You can find it here: C:\Users\[username]\Documents\BioWare\Dragon Age 2\Characters\[character name]\saves\[latest autosave directory]. It will be most probably be Checkpoint.das, you will see Das File written infront of its description.
The editor will show you a screen shown below, and you can adjust the numerical values to increase your various stats.
First Backup your original .das file in another location and then Use Save As on your edited game file.
If you face any issue doing it, let us know and we will try to help you out. If you don’t want to hack your way through the difficult campaign quests, find unique weapons and unique armor that would make your life easier.