Use a PDF merger tool or software
Open the merger application or website
Upload all PDF files you want to combine
Arrange the files in the desired order
Click the merge or combine button
Download the merged PDF file
Use Adobe Acrobat if you have it installed
Use Preview on Mac to merge PDFs
Use online PDF merge services if needed
Use command-line tools like PDFtk or Ghostscript
Save the final merged file with a new name