You just install it.
You're allowed two installations for each Premiere Elements license.
What version of Premiere Elements do you own? Do you have an installation disc or installation files from an online download purchase?
i have adobe premiere 11 but I downloaded it from the adobe site-so i dont have a disk. Im not sure where to find the link to download it to my new mac without having to pay for it again. Where do I get the installlation file?
The link is still on the Adobe site's download page.
Just re-download it and use the serial number you already own to activate it.