Some parts need to be rebuild and it's a great challenge to figure out how to do it or find spare parts, specially in my country.
When I was rebuilding the electrical system the problem was to find a replacement, because I could't find it I had to rebuild it and this is how I did.
Step 1: Identify your fuse box
Your fuse box must look like this:
Step 2: Remember the original wiring order & remove the box
Remove the box from the car cutting the wires as close as possible from the box connections.
WARNING: Do not cut the radio cable, it is the one in the front, it's better to remove the box with the radio wire still attached, is just a few inches long.
Step 3: Remove Fuses and rusty Clips
To remove the rusty old clips is necessary to insert a flat small screwdriver pushing the retainers that hold them in place, then you just have to push the clip to release it.
Then remove 9 clips, except the one in the picture, this one is usually made of copper and it only needs to be sanded and cleaned.