Change "gd_" to something else throughout site

I want to replace “gd_” and other instances such as “gd-” throughout the site I’m working on and instead use something related to the site such as the brand name of the business: eg: “ab_” when creating new post types or doing anything else which uses “gd_”, “gd-” etc.

How can I replace “gd_” sitewide? I noticed that when creating a new custom post type it’s not possible to use a different value.

Thanks