I use the resetsim a lot it seems. Click on all at the same time Control + Shift + C and hit Enter. There should be a blue line at the top. Type in the name of the sim you need to reset. It doesn't have to be your sim, it can be any sim.
I saw a group of sims stuck on a sidewalk, had to go to each one to find out their names then wrote them down. Did the resetsim and typed in the sims name, hit the enter key and he vanished, did that for each one, they were all sent to their homes.
So, it would be if your sim, Sussie Q was stuck type in resetsim Sussie Q and hit the Enter key. She will then be sent home. If the sim is one you don't know, find out their name, Joe MacDuff and type in the resetsim Joe MacDuff and hit the enter key. He will be sent home as if he wasn't stuck.