The Preview application built into MacOS is a powerful tool that allows you to edit and modify PDF Documents. These step by step instructions will help guide you through some of the more popular uses cases of the application.
Viewing your PDF Pages
Open Preview App or open the PDF document you want to view.
If Preview app is not the default app for PDFs, you will need to control + click for secondary options to display and Open With > Preview.
Navigate to the Side Bar toggle switch
and Select Thumbnails
This will allow you to scroll through all your PDF pages in the document.
Rearranging your PDF Pages
-Now that you have the Side Bar showing your Thumbnails
-Click and drag the page you would like to move up or down in the document
Adding additional PDF Documents to your current Document
-While still having the Thumbnails showing in the Side bar on your current document
-Locate the additional pdf File/s you would like to add to the current document
-Click and drag the pdf file/s that you have located to the side bar and they will import into your current document where you can rearrange them as you please
Add Digital Signatures to your PDFs
-Navigate to the page in your PDF that requires a signature
-Click on the Markup icon 
and then click on Signature icon 
If you are creating a signature for the first time, click on Create Signature and create your signature
If you already have a signature created you simply click on the signature you want to use and it will drop that signature into your document where you can move it wherever you need to and resize if needed.
Markup your PDFs
-Click on the Markup icon 
and then select 1 of the options Draw/Sketch 
-Draw will recognize what you are trying to draw and draw a figure for example if you are drawing a square it will automatically create a square with straight lines.
-Sketch is free hand drawing. You can use this to mark up a document as you would with a pen.
Redact Text/Images
-Click on the Redact icon 
and select the text/image you would like to redact. Once it
is redacted you will see 
over the text/imaged that you have selected to be redacted.
