How do i delete custom field cache files?

Hi there,

I have recently changed my blog theme, my new theme only works well if I use the custom fields to be able to create thumbnails etc..

My old theme also had this same requirement.

The problem is whenever I write a new post, there is now a long list of custom fields attached at the bottom, things I used in my old theme, but I don’t need or use anymore with this new theme. It is annoying to have to delete ten or so fields before adding the one I need…

Is there a way I can delete the old custom field files? So it stops popping up?

Thanks