I have an outdoor light fixture for an "Outdoor Lantern" type light. This fixture is recessed into the siding and has a crossbar-style mounting unit similar to this. I'd like to replace it with an exterior flood light to give the patio more light; I've purchased an exterior flood light kit which includes a new weatherproof surface mount fixture box much like this.
Unfortunately, the hole drilled in the siding for the existing fixture is larger than the new surface-mount weatherproof box can cover. I can't position the new box such that there is no exposed gap to the recessed existing fixture.
What's the best way to install the new light?