Let's see, probably the simplest is via Supernet lite, you can do it from any account, not need to be using the issuer account.
1. download here:
http://www.supernet.org/download.php2. install & import your passphrase
3. click the 'advanced' tab on the top bar (click the 3 horizontal lines on the top right first, if you do not see the 'advanced' button)
4. click 'Supernet' on the left nav bar, then select Dividends+Voting
5. click the 'click here to calculate dividends'
6. fill out the relevant fields and activate dividends.
Please note that you can just decide the whole amount you want to pay out, the system sends out the right amount to each account with your asset.
Good luck!