I have been trying to rig my model by following numerous tutorials but i have had no luck. I tried to rig the model using vertex groups and also by using the weight paint tool but both distorted the model. I think it may be because the model has too many vertices but i have no idea how to fix it or what to do. It’s very frustrating and at this point i am willing to pay someone to help me rig my model.
This requires alot more work before it can be rigged, like blendermonkey stated above. This model needs serious retopology so that all the geometry is mostly composed of even quads. This is a required step in creating a rigged character and it is quite a crucial one. Models used for animations tend to have a higher poly count but always take into consideration the way the geometry is organized. This organized approach to geometry allows the mesh to deform without polygons overlapping each other and causing artifacts when you rig it.
I think the way to go with a complex model like this is a “mesh deform modifier.” That is, have a separate low-poly model surrounding your rig, controlled by your armature, and moving your scan through the modifier.