Traduzione in corso passo 4
Now put the second layer on top of the third layer and screw it back together then the first layer just snaps on. i hope this was helpful if it wasn't have your say on why it is unhelpful and i may adjust it.
Note: My Son Richard is 12 and wrote this up in mainly his own words. Both he and his younger sister have a fascination for mechanical and electrical things and I hope they will take forward the iFixit principles as they go through life. Robin