someone give me a guide on this

cheers

if the decals have tape on the top they are easy to apply, I usually use a stip of masking tape at each end of the tube im applying the decal to and mark dead centre of the tape with a pencil, then peel off the underside of the decal and start applying it from the centre working outwards slowly and wiping with a clean cloth as you go to get rid of any air bubbles  

Right mike its 35mm back from the handlebars for the main tube decals, 15mm from under the main tube for the down tube decals.

If its pre march 77 then only black sticker on the front plate or both if after with the union sticker on the plate and black sticker on the downtube 30mm under the last letter (H)

Hope this helps mate.