Leaky 97 Honda Odyssey

Our 97 Honda Odyssey minivan leaks into the rear compartment (where the fold-down seat goes). The rain appears to be coming in through the rear taillight assembly, on both sides. Can we repair this ourselves or should this be done at a shop? We don’t have a diagram of the assembly to guide us in taking it apart. We’re also wondering if there might be a weep hole that could be plugged. Thanks for any advice - Kate.