Consider the below data set and design the steps involved to transform raw data into an understandable and readable format using the concept data pre$-$processing using Sklearn libraries.

$\backslash$table$[[$Country$,$Age,Salary,Purchased$],[$India$,38,68000,$No$],[$France$,43,45000,$Yes$],[$Germany$,30,54000,$No$],[$France$,48,$NaN,No$],[$Germany$,$NaN,$65000,$Yes$],[$India$,40,58000,$No$],[$Germany$,35,73000,$Yes$],[$France$,$NaN,$53000,$Yes$],[$India$,50,79000,$Yes$],[$France$,37,82000,$No$]]$