Hi AlexandriaTrust,
Sorry for the delayed reply.
Since you are using Office 365 for Small Businesses, here are two options for your reference:
Option 1:
If you want to change your domain name server to Office 365.
You should first remove all the DNS records you have created at your domain registrar and then change the name server to Office365.
To change domain name server, please refer to the following article:
http://onlinehelp.microsoft.com/en-us/office365-smallbusinesses/jj655377.aspx
Option 2:
If you want to keep your current name server, you should add required DNS records at your domain registrar. The following article contains detailed information to add DNS records.
http://onlinehelp.microsoft.com/en-us/office365-smallbusinesses/hh416759.aspx
Thanks,
Vivian Wang