How to add marks and bleed to a PDF export

I’d like to use LibreOffice to produce a PDF to send to a print house. The design includes graphics printed to the edge of the paper. The print house would like a PDF that has bleed (space outside the edge of the page that contains slightly extra content, to be trimmed off) and marks (lines to indicate where the page should be trimmed).

I understand that LibreOffice doesn’t have these features built in, but are there some suitable work-arounds that people have found?

As LibreOffice is completely WYSIWYG, the only way to add bleed is to create your document with the bleed. I.e. use a larger than the final page-size, and use the margins to correct for the bleed.

If the PDF is simple enough to not contain stuff until the very cut-margins (only whitespace), you can also use pdf-postprocessing tools to combine two PDF documents. I.e. use a bigger “Bleed” PDF and put the content of the LibreOffice created PDF on top of that.

pyPdf is a python implementation capable of doing that (but requires some understanding of programming to make use of it) is a similar set of programs.
Surely there are some GUI tools out there as well…