Removing the neck of a stratocaster style guitar was designed to be simple and it is. Take off the strings and remove the four bolts on the back of the guitar which go through the neck plate and into the neck.
The neck them simply pulls away.
Two words of warning if the next is stuck be careful not to damage the finish and the neck pocket may contain some shims to give the neck the correct angle, don’t lose these.
Have a look at my video below to see a guitar neck being removed.