Auto-translated
Not Drakkoska, but I'll give you a hint.
Option 1: In any graphics editor (paint.net, GIMP, Photoshop), scale, crop, and do everything as needed.
Option 2: The first option doesn't always produce the best quality. If quality is critical, it's worth using special software to resize images. I use Light Image Resizer.
And yes, there are no forum tools for this.