Product Manipulation

I run a boat export site and have copied the site to a new URL and now need to make all the database fields read something different. For example Hull Grade should be Interior Grade, GPS Fish Finder should be GPS Navigation and so on.

In addition there are superfluous fields (total of 60 in all) that are not needed for the car database. For example Twin or Single Engine field is not needed for a car.

What and how is the best way to manipulate names of fields site wide?

What and how is the best way to add and delete fields from the main structure of a product?

This is sort of like saying, "How do I tune my car?"
One would need to know if they are categories, option values, option names, etc.
All the above are easily edited with the admin section of Zen Cart. If they are in multiple product descriptions, it would be quite a project.
NEVER do anything to a database without backing up and, trying other ways to edit first.