If you already have redirects set up in Yoast SEO Premium and are looking to transfer those to the Redirection plugin, here's a quick guide. Yoast has an Export function. Redirection has an Import function. And both can deal with standard CSV files. So we're golden.
Both Redirection and Yoast SEO Premium have their advantages when it comes to setting up redirects in Wordpress, but I'm not going to go into the pros and cons of each here. I'm going to assume you've already decided to move from Yoast SEO Premium's redirects to Redirection for one reason or another.
In Yoast SEO Premium
The function to export the redirects isn't under the redirects section, as you might expect. It's with the other import/export features in the plugin's tools section.
In the Wordpress admin dashboard, go to SEO > Tools > Export Redirects.
When you hit the blue button, a CSV file will be saved to your computer called wordpress-seo-redirects.csv.
Unlike some plugins these days, Redirection doesn't create a top-level group of settings on the main dashboard side menu. You access the plugin's settings under Tools > Redirection.
At the top of that page, you'll see a link for Import/Export. When you click on that you'll see where to upload your CSV file. You can also specify which group you want the imported redirects to go into.
Delete the Old Redirects in Yoast SEO Premium
Having duplicate sets of redirects set up is a recipe for trouble. So don't forget to go back into Yoast SEO Premium and delete the old redirects from there.