How to remove Toyota fusible link

My 89 Toyota 4x4 truck has 30 amp , a 40 amp,and an 80 amp circuit breaker in an electrical box under the hood on the right side of the engine bay. I was able to pull the small ones out to check them for continuity but I can't see how to release the 80 to get it out.
A year or more ago the battery light and the brake light became coming on intermittently even though the brakes were working well and the alternator was charging the battery so I just continued to drive the truck and ignore the lights. Now however the alternator apparently is not charging the battery and it's time for me to sort this problem out. Any help is appreciated. T I A Doc

was able to remove the bottom of it which was attached by 4 plastic clips then the whole link slid out the bottom after I released a small plastic spring beside the link.
Damn thing tests ok after all that and I'm still looking for a charging system diagnostic procedure for this vehicle . Thanks for your help. DOC

Well for me, mine were in a box that's inline with the positive cable to the battery. It has a little cover, maybe 2" x 3" with labels of "AM1" "AM2" and
"ALT." I peeled back the little rubber boot and you'll get access to the main plastic box. From there, you unsnap the box and then you can unscrew the several 8mm nuts to remove them.

If yours sits in a plastic box that's secured to the firewall, I'm afraid I won't know. BUT, do NOT try and yank them out as they'll just shatter; I soldered a piece of wire between the two pitiful pieces of metal left.

<snip

Glad I could help for a change. As for the charging issue. On Toyota's, both the brake and battery light come on when the alternator's output is less than the battery's voltage. When I crushed the pins for the fusible link and soldered a wire in its place, it held for a while then eventually gave way to oxidiation, etc. One day, heater was making a whining noise and my XM receiver would flicker on and off....then car started bucking -- the battery died because the alternator wasn't charging it because my jury rigged fusible link gave up. There weren't any warning signs since the alternator's voltage WAS > than the battery's

For testing, usually what you can do is fire up the car, turn on everything known to man in it and measure the battery voltage. It should be around 14V or so; mine's 14.5V. If it's below that, it's time to suspect the alternator. On the bright side of things, if the alternator is original (Nippon Denso), repairing it is as easy as replacing the brushes. Those alternators are bullet proof.

When I first tried replacing fusible links, I tried pulling out the entire casing for the link only to have it shatter on me.

What you have to do is open up the plastic case for it and there are 8mm nuts holding the links in place. I actually just went to a junkyard and got a little 80AMP module.

approx, 3/8" x 5/8" . It has a sort of window like an old style household fuse but I can't see any way to open up any plastic case as you suggest. Can you be more specific? Thanks. DOC