Different people use different techniques. I’m partial to wet sanding with fine grit paper, though that may work best if one plans to lightly clear coat and re-decal. That’s what I did on this GP30 to re-number it to a new, later in life, number series:
Another renumber job, this time with weathering:
A long hood is trickier because of hinges, panel lines, and other details. For this AC6000, I used the wet sand technique to remove and replace the original lettering which was in an unprototypically small font:
I think I may have used some Armor Yellow paint to touch up some hinges or other cast-in detail that the original lettering had covered and that weren’t easily sanded. But wet sanding removed the lettering from the flat surfaces. Then some weathering. The key is to work slowly and patiently. It might be necessary to apply a very light clear coat to the area after the lettering is removed
I’m sure others will chime in with their techniques and tips. You might also try a search to find older posts on the topic.
New Year,
RM
