If the frame has the remains of the original decals, The best thing to do is make a record of their locations before the frame is refinished. A camera or phone is useful here, Where this is not possible, you might be able to find images of a frame like yours by using image searches in search engines. Failing that you might be able to find someone in many of the bicycle forums who will supply you with photos showing where the decals are fitted.
The best time to fit new decals is before final clear-coating of the frame so that they are protected from weather and abrasion, so maintaining their appearance. If they are applied to an already finished frame, we recommend protecting them as outlined below.
Ensure that the frame is completely free of dirt, dust, grease and all other contamination before fitting the decals.
Before applying the new decals, mark out their position using masking tape with a clearance of a couple of millimetres around the transfer position, thereby giving it a “window” in which to place it.
Note that the new decals are self-adhesive and are supplied on a backing paper from which they peel easily and on their surface is “Application Tape” which you do not remove until after they are applied. The Application Tape keeps the new transfer in shape before and during application. In this step, peel the decal, with its Application Tape, from the backing paper, taking care not to let the sticky side of the decal touch anything to which it might adhere.
Now is the moment to apply the decal to the frame: Carefully place the centre of the decal in position and run your finger or thumb along the middle so that it is stuck down. Then progressively apply and rub down the transfer working from the middle so that the decal is gradually stuck down without trapping any air between it and the frame.
When the whole decal is adhered to the frame, give it a final rub all over to be certain that it is well stuck down. Then peel off the application tape. Note that decals do not adhere quite as well to some powder coat finishes, so exercise care that you do not lift the decal when peeling off the application tape.
The frame is now ready for final clear-coating. If that is not to be done because the frame is already fully finished, then we recommend masking around the transfer and using a spray-on clear lacquer to put a light coating over the transfer. Use several light coats of lacquer – a heavy coat might soften the inks and cause loss of definition. Check that the lacquer you use is compatible with your paint finish and the transfer beforehand. This is not essential, but it will make your decals look better for longer and it will eliminate the small risk that some solvents will smudge the ink used in printing the decals.