Yeah no problem!
It really depends on how your model's normals are set up, but it looks like your castle walls are just one texture from what I can see so just load up the larger rock wall texture and set object texture to them (I don't know what you do or don't know how to do so forgive me if this sounds condescending), then you use the scale object texture command so it repeats itself, since that texture is oblong you'll want the length value to be about twice that of the height value.
If you need more help I could send you a textured model with the normal map applied and some dbpro code showing how to use evolved's normal shader. I actually have a LOT of medieval art assets sitting around on my hard drive from projects I got bored of.
http://mattsmith.carbonmade.com/