Do this:
1. ) Goto your OLD gmail account and Enable POP for ALL mail that has arrived since xxxx (even if it's already been downloaded)
a.) MAKE SURE to select delete gmails copy when messages are accessed via pop. You don't want to have 2 copies on each account. Plus it avoid confusion.
2.) Goto your NEW gmail account:
a.) Goto settings and find the option "Check mail using POP3"
b.) Click "Add POP3 email account"
c.) Enter your information
d.) Verify
3.) Note the amount of emails you have in OLD account by selecting "All Mail" (gmail shows the count on the right top area)
4.) Watch all of your mail import into your new one. It takes time, if you have couple thousand emails. In your NEW gmail, keep checking the count by selecting "All mail" to calculate your countdown until it's finally done.
5.) After it is finished, go back to settings in your NEW account. DELETE the POP3 account (your OLD gmail).
6.) Goto your OLD gmail and goto settings, forward this to your NEW email; make sure to that you select "after messages have been forwarded, DELETE gmails copy". Again, this causes confusion to have duplicate copies.
7.) We want to have OLD email box empty and NEW email full of your emails.
Now I need to figure out how to import the chats!