404SEF install on Joomla 1.5

Hello Freelancers, We have a very simple project for someone that is familiar with the 404SEF component in Joomla 1.5. We'll need you to install the latest version of 404SEF on our site. We have a ton of organic traffic from google and need to be absolutely sure everyone of these links google is using will redirect to the new 404SEF link. We'll need you to: 1) upload all old urls to the jos_sh404sef_aliases table (or just be sure all aliases from old URLS are created. ) 2)Be sure they redirect to the new automatically generated 404SEF URLs. This should mean that all traffic from google is not lost but is redirected to the new URLs. 3) test to be sure there's no errors with the site I have a sandbox set up that should allow for some testing.