Drill a 3/16" thick X 1 1/2 wide X 8 3/4 long aluminum plate, in two places, in the extreme lower left corner, matching the holes that previously were used for attaching the Bronco secondary latch. Hold the plate with its two holes directly over the threaded holes that used to mount the secondary latch. The right portion of the plate will cover the hole that the Bronco hood pin/spring threaded into. Drill at least a 1/2 clearance hole through the plate, directly in line with this hole. Mount the upper part of the VW latch onto the plate with its pin centered over this large hole. . You need to trim about 3/4" off the left side of the latch to prevent interference with the right mounting bolt. The latch must be attached to the plate with flathead screws so that the top surface of the plate remains flat, allowing it mount flat to the underside of the hood. I used a 1/4 machine screw for the hole remaining in the latch and drilled two more holes near the left end for 10-32 flathead machine screws. Use another screw or bolt to secure the right side of the aluminum plate to the hood brace.
An oval hole, matching the size of the oval portion of the lower VW latch, must be cut with a saber saw in the area where the lower Bronco latch mounts. I made a paper pattern and traced the outline of the cutout onto the sheetmetal first. Trace the hole to be cut so that the center of the VW latch hole will be on the same center as the original Bronco latch hole. Once you cut the opening and file it to accept the latch, the VW latch mounts from the underside. I used four 1/4 bolts, 3/4 long with nyloc nuts to secure it. Some slight grinding or filing may be required along the left front edge of the latch to avoid a tight fit against the backside of the grill. This will be obvious when you start to slide it into place.
I ran the cable all the way along the radiator support, though an existing hole, along the upper drivers side of the engine compartment by where the jack is normally mounted and through the upper part of the firewall, into the interior. My 69 had an existing hole in the firewall and in the 77, I ran the cable through the center of one of the rubber plugs that holds the insulation to the inside firewall. After that, just position the cable release lever in a convenient location on the kickpanel and attach it with two sheetmetal screws. This is why a Dasher cable needs to be used, the Rabbit cable is too short to reach this far.
One more thing, the stock VW spring that pops the hood open a little after you pull the release lever is not strong enough to lift up the heavier Bronco hood. I bought a stronger coil spring at Pep Boys ($1.99), shortened it to eight coils and used it in place of the VW spring. Now when I pull the release lever, the hood pops up about 3/4" and makes it easier to reach through and release the secondary latch. The VW spring worked, and allowed the hood to be released, it just wouldn't lift it up to allow room for your fingers.
I paid $5 for the latch and $5 for the cable assembly at a junkyard. I checked at the VW dealer and they want about $30 for the latch assembly, upper and lower, and another $30 for the cable, so that's not too bad if you can't find one at a junkyard (Rabbit latches are plentiful, Dasher/Fox cables aren't).