Well, one of the first things you should do to your 240sx if you plan on
racing drifting or draging.  The brakes, one of the most common and
the cheaper routes is the one i went with.  Getting a Set of Brembro
Rotors and New 300zx Calipers and a set of Braided Brake lines.  
This conversion is a direct swap...if you have wheels big enough to
give you enough clearance to fit them.  

The tools you need for this job are:   19mm
wrench, 10mm wrench, bleader bottle
kit(Nappa auto parts), Sheet metal cutters.

First thing is to get the tire off.  Jack up the
car and remove the lug nuts and set the tire
to the side.

Next thing you have to do is bleed the
brakes.  Connect a hose to the bleeder
screw shown here.  Then lossen the screw.  
Let it drain into your bleeder bottle until its
full then, tighten the screw and remove the
hose.

Next remove the 19mm bolts on the rear of
the caliper to detach it. Hint: this can be
done while you are bleeding the line.  Once
you have them out you can remove the
caliper by hitting on the back until it comes
loose.  Then remove the caliper and let it
hang to the side. Next take the tin cutters
and cut off the dust shield around the hub.  
Bend the excess in so it doesn't hit anything.
This is how you should look.  Now clean the
Hub good.

Now put the new rotors on.  They should be
drilled for 4 lug.  If not they wont go on.  If
you have a five lug car or you converted
your car to five lug they will work.  Next Screw
the bolts into the back of the calipers and
then remove them.  This ensures they will
engage the threads when you get it on.  
Then put the caliper on the rotor and screw
the bolts in and it should be secure.

Now remove the old brake line from the clip.  
And screw the new line into he back of the
new caliper.  Attach the new line to the
bracket with the clip you just removed.

!!!Make sure the bleeder screw on the new
caliper is screwed in or you will make a mess
like I did!!

Now, without spilling a lot of fluid remove the
old line from the hard line and attach the new
one.  Now tighten all connections and make
sure there is enough slack to turn the wheel.  
Now you should look like this.

Now you have to bleed the brakes.   Hook
up the bleeder bottle to the new bleeder
screw and loosen it.  The bottle should
start to fill. Now pump the brakes 3 times.  
Tighten the screw empty the bottle and do
it again.   Repeat this process until your
brake peddle is firm when you step on it...if
not you wont stop!!!  After each time
ensure your brake fluid is full to prevent air
getting in.  Now your brakes are done.  
Replace the tire clean up and tighten your
lug nuts.  If your calipers and pads are new
then they will make a little noise until you
brake them in.  If you hear a loud
alternating noise, then you probably have
something on cocked and should inspect
and fix the problem.  If you painted your
calipers ahead of time like me then you
should look like this.

In case you were wondering what the
difference was between 240sx and 300zx
brakes, with Brembro rotors over stock
here you go.