the fuse link bolts into the fuse block it doesnt just pull out.
for testing you can try to bend the 2 pieces of the fuse link that are broken when the fuse blew so that they are touching to see if the truck will start. i dont recommend trying to drive it this way.you can also take a thin gauge wire and jumper both sides of the fuse link a wire that is 14-16 gauge will work
you will also have to check all the fuses in the inside and outside fuse boxes some may have blown when the battery was jumpered backwards.
let me know if you need further info on this