Hi there!
i did mine with the assistance of this instruction i found on the internet the last days:
Step 1: Do a practice run
The old woodworking saying “Measure twice, cut once” applies here, at least in sentiment. Before peeling and sticking any chrome edge trim to your vehicle, hold it against the application area and eyeball it. Make sure it looks good from every angle, and that the chrome trim tape is positioned precisely where you want it. Depending on the part of your car getting trim, you may want to use refrigerator magnets of the flat, flexible variety as placeholders to guide where the trim should go. These magnets can easily stick to your door, for instance, and can be removed afterward, leaving no hassle or residue behind. If your trim will circle a taillight or is otherwise curved, wrap your unpeeled chrome trim strips around the target area and gauge the length, placement, and appearance. A good fit, which is what leads to a great look, is key.
Step 2: Clean Up
That means washing your car and your own hands. Stick-on chrome trim works best if it actually, you know, sticks on, and one of the key ways to ensure a strong adhesive bond is to make sure no dust, grime, oils, or whatever get between your vehicle and the new tape. Get rid of all spots and splats, water spots and wax residue. Finish off the area where the chrome auto trim will be applied by wiping the surface down with a paint-safe solvent or rubbing alcohol and cotton towel free of oils, dye, and lint.
Step 3: Stick the trim
This is the step all of that prep and practice was for. Fit a line of chrome trim into place by peeling the backing off and pressing the strip down with firm, even pressure, smoothing it out as you go. Consider rubbing it with a new, clean cloth along the way.
Step 4: Let it rest
Give your new chrome trim strips time to set properly to be sure they stick the way they should. Three to five days is generally considered best, but a 24-hour no-washing window is the absolute minimum. Leave the adhesive alone to let it do its thing, then enjoy a long, beautiful relationship with your new chrome trim.
Hope it helps!
Martin