How rename eml files

Hello: using XP and outlook express
I have a lot of Family history in e-mails that i sent as attachments from Win 98se computer to this XP computer. (sent 4 years ago)
Some of them are named very vague.
How can i rename them?? i have opened them and looked at them but can not figure it out.
Please Advise
MIR11

 

Open each one and change the subject to something that makes it easier for you to know what is contained within the email, then forward it to yourself.

 

Thanks:
I couldn't find any other way.
How much snow do you have??
MIR

 

how rename eml.files

I forgot to mention they were sent as attachments, so when i rename them it updates them and becomes a copy or "second message" then i can delete older one which was an attachment.
MIR11

 

Actually it now apperars that i can NOT delete the original.
I have these in a family ancestry folder in Local Folders
Any help welcome and appreciated
MIR11