There are several. Perhaps the easiest is to use (or find, or make) an invisible driver figure. Not sure there actually is one on DLS, but it shouldn't be hard to make. A see-through box would work.
Or if you have control of the train mesh, you can move the a.driver0 attachment point to Z=-1000m. This is very effective unless you're crossing a bridge over the Grand Canyon.
If you are using outside visible from inside for your cab and the driver figure is in the way of viewing the controls, there's a system for that... but it's homemade. In essence you use option (2) above and script the (substitute) driver figure so it is not displayed if (a) this loco has the focus, and (b) it's in cab view. I've built four locos (actually three and a railbus) this way and it works pretty well.
On the whole, depending on your level of experience, the first option is probably best. Find or make an invisible driver and substitute that mesh for the one in the driver asset you want to (not) use.
