Broken Fiesta Rolling

: Good morning,

change the wheels of my Ford Fiesta Gasolina in 2009 a month ago in the Norauto for Cooper Zeon Cs6 195/45 R16 84
v Your help ....
Questions:

How many bearings do I have to change?
one or all ??
If they are all ... how many would it be ???
Do you recommend any concrete model?
Would you have to change something else?
What do I have to look at or take into account so that I do not talked /tango in the Norauto for this management?

A Million Thank you in advance !!!!

Signed: a megarubia for mechanics