How do you fire a bitizen from their job on tiny tower

Click on the bitizen, then n that pqg, click JOB, then either select a new job from the list, or at the top of that list is "no job" which keeps the bitizen, but makes them unemployed. Ot, simply evict hm/her if you just don't want them around at al, any more. In both cases, though, you have to make sure the shop they are I is not being stocked when you try this.