Complex sentence: Váli is changed into a wolf by the gods, and rips apart his brother "Nari or Narfi", his guts are used to tie Loki to three stones, the guts then turn to iron, and Skaði places a snake above Loki.
Split into simpler sentences: Váli is changed into a wolf by the gods, and rips apart his brother "Nari or Narfi". His guts are then used to tie Loki to three stones, after which the guts then turn to iron, and Skaði places a snake above Loki.