First step is to prep your car. You need to take everything off the front end, including the hood. I won't go into details here because other threads have covered this in Silvia conversions.
The hood is self-explanatory. The headlights have several bolts. The bumper and support come out as a whole after you've undone the fenders. The fender liner comes out after undoing the clip.
The only tricky thing is the fenders if you haven't done them before. There are bolts visible in the hood. There are several bolts that are hidden and not visible unless you've done it before.
Look at these pix closely. The arrows indicate the direction you come at it with a socket.
There is one behind the door. You have to open the door fully and perhaps use a swivel extension or u joint to get it.
There is one behind the fender. You have to come at it from the front wheel after you take out the fender liner. TIP: cut the steering wheel all the way to one side to give yourself more clearance. Then turn the other way and work on the other side.
There are a coupel of bolts under the car where you usually jack up the car. They may be rusty or beat up so be careful.
The front is more intuitive. Just follow the fenders at the front where it meets the bumper and unbolt everything.