mounting 2nd propane tank

[wayne2007]

I have a 2005 Rockwood p/u model 1910. I want to add a second propane tank. I bought a kit from the local camper dealer and there doesn't seem to be a mounting holes that line up with the mounting plate. I'm guessing the two tanks sit inside the mounting plate? Do I have to drill some holes to mount it? Any help would be helpful.

Thanks,
 Wayne