Send a mail to the old maintainer to notify him about your proposal.

You need a garage.maemo.org account, to log in www.maemo.org and open the page:
http://maemo.org/packages/view/openvpn-applet/

Select the link:
"Request to be maintainer of this package"

Then, techstaff (in the detail, the garage.maemo.org maintainer) will reply to your request.