>>10723660These will fuck up your piecies if you'll cut too close, cutting the sprues can also snap the gate point off the part leaving a nasty indentation.
If you haven't gotten single-blade nippers of ANY kind, try separating the whole runner into smaller parts and then freeing the piece with more than a bit of the gate still on it, then give it another snip closer to the piece and then clean up with your hobby knife of choice.
pic related - i cut it right againt the part with similar nippers.