Photo 1:
Use slow set epoxy, available at model supply or hobby shops. You'll also need some strands of fiberglass. I prefer getting a piece of 24 oz. cloth, and taking it apart. Cut the strands as shown. Use small wooden sticks to stir the epoxy, and for placing and coating the strands.

Photo 2:
Tie the strands around the neck of the broken pin. Use two strips, fanning the ends out onto the plastic. Tie all of the pieces you want, for the neck, before applying any epoxy. It is very hard to tie knots in wetted strands.

Photo 3:
Work epoxy glue under the broken pin, and into the strands. Take your time, and get the strands fully wetted. You have about 15-20 minutes working time with this epoxy.

Photo 4:
You may let the epoxy set until it is partially gelled, as shown in the inset photo. As long as the epoxy is still tacky, new epoxy will cross-link, forming a strong bond. Now add more strands, over the tied-on strips, to increase the bond surface. Note the fanned out, fully wetted ends of the first layer.

Photo 5:
Here's the finished pin, fully glued, wrapped with fiberglass, and VERY strong (much stronger than the original part).

Photo 6:
I broke one of my lower fairing mounts off, and lost it in the crash (deep sand is bad that way!) I fabricated a new eye, out of thin aluminum and a rubber grommet. With holes drilled in the remaining bits of plastic (and the aluminum), fiberglass strands were laced through the holes. Apply epoxy and more strands, as shown previously, and you'll have a very good repair. HINT: For position critical repairs, hot glue the part in place, then tie, wrap, lace with fiberglass strands and epoxy. The hot glue remains buried in the epoxy. I've also repair cracked panels by running lengthwise strands of fiberglass at the edge, before applying glass cloth. Build the edge thicker than the general repair.