We don’t manage people’s personalities to make them better workers. We manage objective incidents, one at a time when an employee’s behavior or performance is falling below standards.
Say we have an employee that is nice, easy to work with, is really funny and likes to goof around a bit.
They have a pleasant, fun personality but the goofing around gets in the way of their job at times.  Maybe also they’re a little too gregarious and they lose focus chatting it up here and there.
This is a person with a big, warm, likable personality but their work performance is just not where we need it to be.
Here’s the type of situation that is so easy to just let go and not deal with.  
This person is well liked and how in the world can we ever start to wrangle in their personality to make them a better fit for their job. 
Do we really want to be the “big-boss-bringdown” person clamping down on them?
Do we really want to say to them, “could you just cool-it here at work and generally be more serious about what you’re doing?” 

Do we really have the skill to take on the task of changing a personality this big?
The good news is we don’t have to – refer to the first sentence up top.
Their personality is not our business. We do not manage personalities.
We narrow our focus and manage specific incidences – one at a time.
From the start of their employment, if we see a particular incident that didn’t meet expectations, we do little clarifying check-ins.  Not focusing on their personality but on the observable facts of performance and behavior that took place.
Not, “Hey, could you not goof around so much when you’re restocking the bags. “This way, “I noticed all the bags were not stocked before your first break. What do you think kept that from happening? “Manage the objective incident, not the personality.
Then if things don’t get better, you manage the next incident, then the next one while increasing the formality and structure of the conversation. You never have the same conversation twice and never have to lose your appreciation of who they are.
Managing takes place one conversation at a time, providing clarity to an employee, not the impossible task of trying to change them. 
Managing big personalities can seem overwhelming; it’s a good thing that’s not our job.