Strictly, you can never actually change an LNAB. The process to "change" an LNAB creates a new one and then merges the old one into the new one. This is a good substitute, but the change log will stay with the old one and won't be fully accessible.
Same with a freespace. To change the URL you can make a new one and merge the old one with it at [[Special:MergeSpace]]. But the old name won't entirely go away and you can't reuse it once you've merged it - the redirection is fixed for good.
Never create a freespace with double-quote marks in the name. You'll find it doesn't always work, and when you try to merge it to get rid of it, that's one of the times when it doesn't work.