Sure you can.
1- Plug a USB sticj into your PS3.
2- In your PS3 menu, go to Save Data Utility.
3- Select the NHL Legacy Rosters you want to share and press Triangle, then Copy them in your USB Stick.
4- Remove your USB stick and plug it into your computer.
5- You have a folder named PS3 containing your Legacy Rosters (PS3/SAVEDATA/BLUS...).
6- You must archive your folder with WINRAR to be able to post it on the forum. On your desktop, right-click and select New WINRAR Archive, name it, and drag your PS3 folder into your newly created WINRAR archive.
7- You can now post your rosters on the forum by clicking on the Manage attachments below the text box.