Same thing happened on my instrument checkride. Did oral, weather went south and had to come back for practical. I stressed over the practical twice as much. I think it is better though because the examiner already knows that you know your stuff so it puts them in the frame of mind that you are ready. Just my thoughts so your milage may vary.

Talk your way through everything as was mentioned. That way the examiner already knows that you are not behind the airplane. Remember the little things and just relax. I tried to imagine that I was flying by myself and did exactly what I was taught to do. Also if they DME pings you on something don't be afraid to ask them a little about it. That shows that you want to learn why they said what they said. Maybe you were taught the same thing only differently. Plus it makes them feel like they are teaching you something. Win-win.

Good luck just relax and fly the plane.

 

Not bad advice but be very careful what you ask and don't gig yourself into a hole. You don't want to expose any more ignorance than you have to.