OK, I know I must sound like an idiot, but this seems a bit complicated to me and I don't want to screw up my site any more than it is already. I have been advised on this forum to update the theme, which is Woo Simplicity. I needed to buy it since the guy who built the site is no longer with us (I home there is no difference between "standard" and "developer" for this purpose). I have downloaded it, but how do I update it on the site?
It seems to be telling me to go to the "custom.css" and change it there, but it is not clear to me how I do that.
Can someone hold my hand a bit? :)