Can anybody help me to bake 5 textures into 1

Hi, i need to bake 5 textures to one and i have no plan how to handle this in blender. I watched some tutorials in Youtube but even after that, no plan :(.

I uploaded a model of a castle today : https://skfb.ly/6WOSO

This model consists of 5 textures, I need just one. I think this work will be done in some minutes for an expert.
If somebody can help i will send the model.

Many thanks in advance, Harald