You need to upgrade 8.04 to 10.04 first (from LTS to LTS versions). Then you
can upgrade 10.04 to 10.10 without going through the intervening releases.
However, upgrades are not reliable in my experience and doing too much
upgrading increases the chances of something going wrong.

Hardy (8.04) was a LTS release and is good for six more months. Lucid
(10.04) is also LTS and has a longer shelf life than 10.10. My
recommendation would be to upgrade from LTS to LTS and stop at 10.04 unless
you have a really good reason to want Maverick (10.10).

Lucid expires in 13-04 and Maverick expires one year earlier.