PDF shrinked oversizes pages.

Dear Community,

I have a 30MB PDF that I have to shrink oversized pages. I do that clicking in print, choosing print to PDF  then clicking in shrink oversize pages and then Print.

The problem I found is that when the process finishes my new PDF is 200 MB and I have to upload that into a website that only allows  below 50MB PDF-A files.

Do you know how can I fix this problem?

Thank you.