Nope any way works, but is time based.
Spoiler
You need to visit it once after, go forwards a bit indoors then a scripted event happens.
After which you wait again a bit, then it should reopen.
This. Wait 3 days after you get the new Sheriff and reenter. After the scene, however you choose to end it, wait 3 more days and come back.
I've just installed Primm Slim as the new Sheriff all the time since it requires the least walking around/traveling and only needs 30 Science. Plus you can here him on New Vegas Radio sometimes.