Did you replace the drums and not the brake shoes? 
Remove all the other nuts. Prying the wheel out to push on the back of the offending nut try to loosen it. It may catch and thread off. If no you may have to cut it off. Once off you can remove the flange and replace the damaged stud. It is probably best to replace all and all the nuts while you are at it. The nuts especially are consumables. 

Dennis
 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Joe Novak
Sent: Monday, August 24, 2015 12:02 AM
To: vanagon@GERRY.VANAGON.COM
Subject: spinning rear lug nut

evening all,

i replaced my rear brake drums this weekend on our 86 westfalia.
first one went great - pretty easy job.

second one came off and new one went on, no problem...
but when i went to retighten the lugs,
one decided that it wanted to spin in place.
i think the stud has striped itself free of its splined home on the hub.

does anyone have experience with this? if so, how much work am i in for in getting this nut free so i can replace the entire hub assembly?

cheers,
jvk