Follow these steps to add pages from the PDF file :
Step 1: Open the Adobe Acrobat DC software and upload the PDF using the 'File' > 'Open' button.
Step 2: From the top menu or the right pane, select 'Organize Pages.'
Step 3: To add pages to a PDF, click the 'Insert' button on the toolbar. It is possible to input pages from files, clipboards, scanners, and websites. After that, you can drag and drop pages to reorder PDF pages as needed.
Step 4: Select a folder or click the 'Choose a Different Folder' button and navigate to the folder you desire. To save your PDF file, give it a name and click the 'Save' button.
Follow these steps to remove pages:
1. From the left-hand menu, select Pages. Each page of your PDF will be presented as a thumbnail image in the Pages panel.
2. Click on the page you wish to delete to highlight it. Holding Ctrl on your keyboard while clicking allows you to highlight multiple pages.
3. Right-click on any of the images that have been highlighted.
4. Click the Delete button. A popup called Delete Pages will appear.
5. Click OK after selecting Selected.
6. You'll see a confirmation box pop up. Yes, should be selected. The pages will be removed from the system.