**Split and merge PDF files**\\
Install ''pdftk''\\
<code>
sudo apt-get install pdftk
</code>
__Split a pdf into many one-page files:__\\
Copy and paste the pdf into a temporary directory\\
Then //burst// it into many one page pdf (you will get many small files like pg_0001.pdf, pg_0002.pdf and so on)
<code>
pdftk largepdfile.pdf burst
</code>
Delete the original pdf and the pages you don't want, then\\
__Merge everything with__
<code>
pdftk *.pdf cat output onelargepdfile.pdf
</code>

You can also use ''pdfshuffler'' to cut out/trim the pages in the document. You will then have to compress the 'trimmed' file with ''ghostscript''
<code>
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf
</code> 