Changing cell contents

Hello,
I am looking for a macro to that will change cell contents.

Example:
Column B has both regular names & login user names. I would need a macro to change the login user names to the existing regular names that are associated with them.

mo2sjes5 = Stan Jessup
ca7tlan9 = Taylor Lane

Both Stan & Taylor's names are in column B, but so is their login user name. To help sort this column better, I would need a macro to change their login names to their respective names.

Do you know of a macro to do just that.

Thank you so much for your help on this. It is much appreciated.