How do you fix the hood latch under the hood of a 2000 olds alreo?

you will need to be more elaborate. there is a cable that releases the hood is it seized? if so you will need to use a long screw driver to pull the arm back. there are 2 pieces of metal hinged together they are known to rust and seize. there are small springs that return the latch assy but they are weak and need a smooth working assy to work properly . finally your latch needs to be aligned properly or it will not work properly. If your latch is bent or seized completely go and buy a new one , if you take it apart it will never work right again anyway.