You will need to grab the complete distribution from the products page which you can get to from here:
https://sybase.subscribenet.com/
You'll have to authenticate so hopefully you know your account information or know someone who does.
This will take you to the available products page for your account. Once here, if you have licenses for it, the SUP should be available. If not you'll have to contact support. When you click through you should see the latest version. Again if you don't you'll have to contact support.
There should be 4 zip files to download that make up the platform. There are also 2 zip files of documentation. I would download all of them. Once you've grabbed them extract them all into the same directory. Find setup.exe and you should be all set.
If you do happen to extract the downloads into separate directories just copy the modules directory from each distribution to the one where setup.exe lives. It won't work unless all the files are in the same place. I learned this the hard way.
Good luck!