That's a tough one to give a generic hint to. It's an open-ended level, there are at least two fairly distinct approaches that I am aware of. I can offer these two general hints:
- Keep in your mind how to change connections for Low Voltage Nodes (that is, the change must come from the other end and when you connect the path to the LV node it must be fully valid)
- Try to leave yourself enough space to move paths around wherever possible. You can easily get yourself into a dead end if there is no way to relink a connection.
And one very specific regarding the last node, encoded with rot13:
Gur qrirybcre-vagraqrq fbyhgvba gb gur ynfg pbaarpgvba vf gung lbh arrq gb eryvax gur oynpx cngu gjvpr va n ebj. Gur svefg eryvax vf gb tvir lbh fcnpr sbe gur frpbaq eryvax. Gur frpbaq eryvax vf gb jenc nebhaq gur plna (tbvat ol zrzbel abj, V pna'g npprff gur tnzr evtug abj) abqr gb perngr n cngu gb gur gbc-evtug bar.