With SEOPress Free, you can quickly remove /category/ and /product-category/ (or any other category base and/or product category base defined from the Permalinks settings page) from your post and product category archive pages.
To do that, go to your WordPress admin, SEO, Advanced settings page, Advanced tab.
First step is to enable the Advanced settings by checking the blue iOS toggle (ON by default).
Then check “Remove /category/ in your permalinks” and “Remove /product-category/ in your permalinks” options.
Finally you must Flush your permalinks from Settings, Permalinks and clear your cache if you have one on your site.
We’ll automatically redirect old URL to new ones.
We recommend to define these settings from the very beginning of the creation of your site.