NSSCG or Natas Spin Set Cust Glitch is pretty simple and does basically what scg does in the other games it allows you to get into solid places you can't other wise glitch into.

First be in walk mode and set cust beside what you want to get to. usually the object should be on your left side. now find something to natas spin and while in a natas spin bail if you bail just right so your still kinda spinning pause mid bail and goto cust. if done right you will slide sideways into what you were trying to get in.

BGSCG Does the same thing only using a grind instead of a natas spin. Just bail to which ever side the object you want to get into is on. if your in walk mode and the object is on your left then bail grind to your left.