for just about every duramax, especially that early of a model there is a spin on filter located at the passenger side towards the rear of the engine.
it is underneath a filter head with primer pump top, bolted on to that side of the engine.
If you are having difficulty keeping the engine running the primer pump o'rings may have failed.
Duramax engines do not use a lift pump to push fuel up to the engine, so the filter has to be primed to fill it and then bleed off any trapped air before the pressure pump can take over.
Hope this helps.