Question regarding ISBNs from previous editions

Hey all -

Some of you may be aware that I recently pulled the rights to my fantasy series from my publisher (which is circling the drain as we speak). Said publisher promised me the cover designs for my four books, and paid the designer a $15/book fee to remove the publisher's logo. The designer delivered the designs to me today, and the logos are, indeed, gone. However, she didn't remove the publisher's ISBNs.

My agent is trying to place the series elsewhere, but while she's submitting, I'm trying to get my ducks in a row in case there are no takers and I end up self-publishing. In that event, I can't use the ISBNs on the covers, right? I'm assuming I'll have to get new ISBNs, but can one simply "paste over" the publisher's ISBNs with the new ones?

I'm at the very beginning of the self-publishing learning curve, so please bear with me if this is a really dumb topic (and mods, if this would be better off in the Self-Publishing forum, please move it there).

Thanks, Marissa - I figured that was the case. And yes, I mean that the old ISBNs are on the jpegs she sent me. I was balking at asking her to remove the ISBNs as well, since I suspect she'll want another fee to do that, and I doubt I'll be able to crowbar the $$ from the publisher. I've emailed her back and asked her to remove them, and maybe she'll be nice and do it without an additional charge.

A friend just pointed that out to me. Thanks, ironmikezero.