When cutting P.E parts, you can use a X-Acto knife as mentioned, (but instead of the #11 blade I would recommend blade # 12, 22 becuase of the curved blade which makes it easier to cut by 'rocking' the blade across the P.E gate on a very hard and flat surface) however, Xuron and Model Master make great P.E cutting shears which work great. The tool will cut very cleanly and only a few passes with a file will clean the P.E of any remaining stubs. If you chose to cut the P.E parts with a X-Acto knife, make sure you use some low tack tape on the bottom of the P.E fret so that the parts wont fly off the table and get lost.
Also, as stated above, superglue (CA Glue) works the best. Use a toothpick or a piece of thin wire to apply the superglue to the part.
I hope this helps.

Kind regards.
Martin