Step 1: Next install the neck plate with the screws only sticking out about 1/4 of an inch. This will help line everything up when you go to install the neck.
Step 2: Next place the neck on the screws.
Step 3: Screw the neck in and remember to rotate which screws you are fastening down (the same idea as putting on a car tire). Tightening a screw all the way down at once can cause damage to the neck.
Note: When you install the neck you might have to use thin pieces of cardboard to shim it so the intonation is correct.
Step 4: Install 2 strings only.A fat one and a skinny one (the E strings). That way if you have to take the neck off to shim it more, you're not taking off all the strings.
Step 5: Now just tune your guitar and you are done building your Stratocaster!