I have a 2009 Honda Odyssey, and I need to replace the tailgate light assembly on passenger side.

I was able to pull the old assembly out, but can not install the new assembly. I tried to push the assembly in, but the two plastic pins seem to get in the way. I tool the two plastic pins out, but I still can not align the studs back to the body. Do I need to replace the cover above the hatch?

Are you talking about the inner tail light, the ones on the lift hatch itself? If you are, you have to remove the trim panel from the inside, as well as the license trim. It looks like there are 3 locating dowel pins and 4 nuts that hold the unit to the tail gate.

Align the pins with their respective holes and it should go together easily.

Does the replacement assembly match the one that you took off?
Can you post pictures?