To re-attach the Chrome letters you can use 3M double sided adhesive or even a masking tape. These two products are very effective when re-attaching Chrome letters on cars. They will help stick the letters very nicely and firmly.
Go to the store get you some good 3m double sided tape and an exacting knife. Make sure and clean the part and wipe off there area to be applied with some sort of alcohol. If you don't have any you can use a wax and grease remover or winded because it has a lot of alcohol in it. Hope this helps