What I'm hoping to do is be able to change the turret on a tank. For example, change the battlemaster turret to the technical gunner. Or the quad cannon turret to the scorpion tank turret. Can this be done in the ini files or do I need to create a new model? Are there any existing tutorials about doing this?

Thank you!

You can to a limited extent change turrents in ini files by modding the draw module to hide the original turret SubObject and then add a new draw module to draw the new turret or draw the whole vehicle but hide all the subobjects except the turret. Try both just drawing the whole vehicle and hiding the body, and also attaching it to a named bone in the original model (like how technical gunner is attached to the bone in the truck model). Depending on the shape and size of the model one method might work better than the other. See the PT boat for an example of adding the technical gunner to the boat but not attaching it to the bone (unlike the technical, they did not declare the extra public bone in the boat model draw module). This is why the boat gunner is drawn half inside the floor of the boat - he is just placed at the origin rather than at the bone.

If you are doing a map.ini mod this is your only option. Far better is to create a new model.