Using LaTeX's pdfcrop
To crop a DHL Paketmarke to the part that goes onto the parcel, you can use the following command with LaTeX's pdfcrop command.
Download and installation instructions are found here.
pdfcrop --clip --margin "0 0 0 -450" DHL-PaketmarkeXYZ.pdf cropped.pdf
Alternative using pdfcpu
Download and installation instructions are found here.
pdfcpu crop -- "[10 480 550 780]" DHL-DHLPaketmarkeXYZ.pdf cropped.pdf
Or with some label layouts also this works better
pdfcpu crop -- "[10 490 520 760]" DHLPaketmarkeXYZ.pdf cropped.pdf