Opening the hood when the cable is broken on the handle end can be done IF you can get TO the cable remnant and put a vise grip on it to pull it..
IF you cannot do THAT,
There are two rubber 1" plugs on the cowling which can be accessed from the windshield side.
They are tucked back in and under the hood ..You may have to stop the windshield wiper in an upward position to get access to the rubber plugs.
One is on the driver's side about 2" left toward the fender from the latch mech beneath the hood.
Use a small dull screwdriver to push the rubber plug into the engine compartment..
Then you have to bend a longer flat blade screwdriver so's it passes thru the hole and jogs 90 degrees right for 2" and then bent 90 degrees left then straight for an inch or so,..
Press down on the hood latch to release it..
Passenger's side latch is easier as the rubber grommet is straight in from the hole ..
For those of you who have a C3 of later vintage, open the hood and take a few pics and measurement..or better yet, get out the torch and make the tool and set it aside..
There's several fair videos on YouTube that helped me..tho they were not perfectly done..
Jim
______________