Sign in to Acrobat Web at https://documentcloud.adobe.com with your Adobe ID and password, or with your social (Facebook or Google) account.
You can split a PDF file into multiple PDFs using the Split PDF service.
Steps to split a PDF file into multiple PDFs:
In the top navigation bar, click Edit > Split PDF.
Do one of the following to select the files that you want to split and then click Continue:
The PDF pages are displayed as thumbnails. Click the dotted horizontal divider lines to select the page to be split into a separate PDF, and then click Continue.
The dotted lines turn into a blue line upon selection. You can select up to twenty divider lines to split your PDF into multiple new files.
In the save dialog box, choose to save the new PDFs in the same folder or a new folder. Click Save.
The PDF is split into separate files with the part<number> appended to the filename and uploaded to your Document Cloud account.
The Recent section at the bottom area of the home page lists all the files you’ve split recently. Alternatively, to see the list of all your files, click Documents in the top menu bar.