A recent discussion on our IRC channel reminded me of my old tool
presto which can modify the UID of any running process on FreeBSD via write access to
Yes, of course this not a security problem, but sometimes this comes in handy - E.g. if you need to promote a running editor to really write that file now.
I dusted it off, converted the old RCS to git, updated it for current FreeBSD versions and put it on github here: https://github.com/Sec42/presto - so if you want to play around with it - go ahead :-)