How to pull texture/patterns from game

TS4 doesn't work with patterns (like TS3 did), but just with regular textures (what you see when you extract the texture is what you get, essentially), so you'd have to recreate the pattern yourself from the texture, or (if lucky) find resources from someone else who has made the textures into patterns.

If you have a decent portion of a texture/pattern, it's not too difficult to make it into a seamless pattern, depending on the difficulty level of the pattern, of course. A pattern with a high level of details is a lot harder to work with than one with few details.

There are plenty of tutorials on how to make seamless patterns using bits and pieces from a texture. Here's one, and here's another (both for Gimp). You can probably find others, too. In addition you may also need to know how to separate out the pieces, maybe also adjust/fix colors, because there are often too dark or too bright patches, sometimes also completely replace patches of color.