I'd like to replace just one of my current pots with one of lucas's pots, but how do I do that?? All the pot images are in one image...

I change the goldpot with each of the pots i like then one by one I replace them

you can overwrite it though...

I know that is how I do them one by one

Yes, but you're doing that by editing the images. I think what SP is saying is that she can't replace just one pot by using one of the mods, since the pot.png file contains all 7 pots. The only way to replace a single pot is by editing the image file, which is not something that everyone wants to do.