Thread:Ragnarok6354/@comment-11300501-20150503004256/@comment-24187738-20150512004628

Not too sure about this since I made a hash of it the last time I tried, but you most probably need a program like Photoshop or a free alternative like paint.net. Then you use tools like Magic Wand to select the background which you delete, while retaining the character. It's really just working on the pixel level till it's done.