[lovewindows]

As the title says , How ? it's that plastic / vynl type of stuff. 

[Gav Camm lammy 283]

heat gun warm up the letters n vinyl gently it shud
peel off m8

[gsw]

wallpaper steamer works a treat  (just use the hose with a steam jet not the plastic tray thing) but your thumb nails go soft after a bit from all the picking!!

[cleewindows]

had to do one the other week,heat up with the mrs hairdryer,get a scraper and scrape off as you heat up the vinyl.
Rub what you can off and then scrape the residue left off and then polish yoir van and you will see any glue after you have polished,if there is use scraper again.
Job done.doesnt take too long.

[thewaterwizard]

heat gun then use this to remove glue
www.autoglym.com/enGB/product-proddetail.asp?v06VQ=GD&Range=1

[Central Window Cleaners]

heat gun and then wd40 to remove the glue worked for me

[babs2020]

when was in the car  game  used  a hot jet wash  and the  tar and glue  job done

[lovewindows]

Cheers chaps.