Cannot access https:// version of web site, need to remove A record

I built my web site years ago on sitebuilder.  They sold themselves to another company, and now my A record is pointing off to lala land.

To fix, I need to remove a specific A record and apparently something magic is supposed to discover the new address (according to the new folks supporting sitebuilder).

Where can I find my A record and remove it?

thank you in advance...