It is most likely going to be a mad Dash for the woods. Passing isn't hard but getting comfortable with it is. Your lower back is probably going to ache a lot during the race since you don't usual ride as hard as you can for 1 hour straight.

I would say if you are a good rider or confident in your ability to hang that you go into the woods in the top 1/3 of the group. Hang back and watch what is happening for the first few minutes. If you need to pass don't hesitate, call the side you are coming on and just go. The rider ahead should not block you and if they do do your best to get by when the opportunity presents itself.

Try to find someone faster than you and stick to their rear wheel. I use this to pull me around at a race and then try and dig deep for a fast finish. You are going to feel terrible while racing or you are not riding hard enough. This is part of it but the sense of accomplishment at the end is completely worth it.

GOOD LUCK!