1)Go to google and download reshack.
2)Open up Reshack and at the top you should see a File button, click that.
3)Up at the top where it says Look in: click the arrow point down beside the white line.
4)Choose the endless online gfx folder. At the bottom hit the arrow and choose All files (*.*) Then choose what gfx you want to patch, ex:gfx001.
5)Hit the View button up at the top, and then hit Expand tree.
6)Where the little green circles are is where the gfx's are. Right click the one you want to edit.
7.)And then click Save [bitmap (number of gfx):0]... Save it somewhere like your desktop.
8.)Open it up with paint. Then edit it the way you want it.
9.)Save it, the go back to Reshack and right click the same gfx as before, and hit replace resource... Then hit the Open file with a new bitmap and choose the edited gfx. and then hit replace.
10.) Make sure your EO is closed before going to File and hitting Save. Or else it won't save.
That's it :).