No need to change, your darkcoins automatically became dash.
If you want to exchange to another currency, just use your favorite exchange (check dash exchanges on coinmarketcap)
I understand that i have dash now. But what do you think about it? Should it grow up in future?
Honestly, I think Dash has the biggest future of any project. But if you want to cash out, there is a list of exchanges at
http://coinmarketcap.com/currencies/dash/#markets and choose one that's best for your location.
Dash's Evolution is going to seriously revolutionize the use of crypto currency. It will make it super easy to use, and hopefully we will make market inroads this upcoming year.
But if we slack off, and don't keep pushing for adoption, things could wane.
Thus we have to keep being creative and find users who NEED us! If you have ideas, please share here:
https://www.dash.org/forum/threads/we-need-merchants-using-dash.11308/Thanks!