Before replacing the keys, take your lint free cloth and dampen it with your cleaning fluid (don't put the liquid directly on the keyboard), give the surface of the keyboard a good wipe over ensuring to clean as much as possible any keys that you haven't removed.

When the keyboard is nice and clean replace the keys according to your notes or if you have just removed the letter keys use fig 1.4 as a guide, to put the keys back on position the key in place and press gently but firmly until it clicks home.

After replacing all the keys give the keyboard a quick wipe over with your dry cloth and you have a nice clean keyboard.