Can ETH still be witdhrawn from theDAO?

I never bothered to withdraw my funds from the DAO after the fork, because I thought it was a very low amount. Turns out it was way more than I thought.

Can I still withdraw that?

The wallet I used was a mist "contract wallet". I have the key of the account that controls it.

I found the withdraw contract (https://etherscan.io/address/0xbf4ed7b27f1d666546e30d74d50d173d20bca754#code), but I don't know how to call the withdraw() function "from" my "wallet contract". In fact I don't even know how to import that "contract wallet" into metamask or MEW or anywhere else (I can import the controlling account into both).

Are these wallet contracts still a thing?

Any help appreciated.

I will be generous to anyone who helps me substantially in recovering the funds.