You should be able to vote with the 0.5.2 wallet. Click on the “Motion vote…” button and then on the small “+” to add a line. Paste the motion hash in this line and click OK. Please also make sure to add custodians and consider parking rates as discussed in several recent topics.
Note that you will only vote if you find a block and your coins need to age 10,000 blocks (about one week) to be eligible for staking. A virtual box with the Nu client would work, but I don’t think its necessary.