Open the PDF in Adobe Illustrator
Go to File > Open and select the PDF
In the Import PDF dialog, choose the page you want to edit
Repeat the open process for each page you want to rearrange
Copy the artwork from each opened PDF page
Create a new Illustrator document
Paste each page’s artwork into the new document
Arrange the pasted pages in the desired order
Use the Artboard Tool to create separate artboards for each page if needed
Move each page’s artwork onto the correct artboard
Save the file as a PDF from File > Save As or File > Save a Copy
In the save options, enable Use Artboards
Set the page range and order as needed before saving