You can try the Foxit PhantomPDF. There is a feature named “Split” in the app. You can set some configuration as you like. For example, you want to separate the 10 pages into two documents, one with 6 pages, another with 4 pages. Then you can set the “Max” page as “6”. Then you will get two new PDFs.
Just change the “Split” feature to “3” or “2”. To split the first page, just click a “0″ at the start of the Page number. Set “Max” as “6” in the settings. Then set “Split” to “3”. To split the second page, just click one of the two letters in the “0″ after the Page number. Then choose in the pop-up menu “2‛ split.” To split the document again, just double-click on the “0” between the Pages “10″, and “6″. The last page will appear again. The second page is the “same” as the first. The “split” is between the two letter-lines. So you can split each page by 9. 0. 4‛. You will get two separate PDF documents. There is a button ‑‑‣ “Split 4‛” that you can press to.