pit stop and drive through

hi guys anyone can explain me how to properly do my mandatory pit stop and how i should perform drive through penalties.
when i decide to do my pit stop should i call the pit in?!?or just go in?!?

 

with mandatory pit stop you have to change at least two tires, extra fuel is not required.
When you call the Pit in before getting to the pits, you save a little bit of time at the tire change

 

and how you do a drive through penalty??

 

If you call a pitstop early, your pit crew can get ready for it and therefore it's gonna be a couple of seconds shorter compared to just entering the pitlane. For a mandatory pitstop however you need to change tyres of at least one axis for it to count. If you want to make a drive through, you need to select a corresponding option in a pitstop menus before you enter a pitlane as far as I remember

 

After the last update the difference of time winning is as good as gone