Use Trados Studio 2017 to proofread English Monolingual editable PDF?

I have a huge English PDF (editable) to proofread. I'm thinking the best way to do it is this:

 

Step 1.) Pull the text into Word 2007 (which is what I'm using - otherwise I could use the PDF editing functions in later versions of Word);

Step 2.) Apply proofreading tools and check;

Step 3.) Open a Trados Studio 2017 project - the PDF as a single file;

Step 4.) Copy source to target throughout, making changes where they're made in the Word document after Step 2;

Step 5.) Save Target As.

ONLY STEP 4. seems like a hassle. Does this seem like the best approach to you? Any other ideas? Any problems with this plan?

 

Tnanks in advance!