this done by adding power factor correction capacitors (PFCC) , you must know the following data:
1- the load (kw) that you need to improve its power facto
2- the old power factor value
3- the new power factor value
then you can use the power factor correction tables to calculate the required capacitor KVAR or using the PFCC calculation spread sheet which you can find it in this link:
PFCC calculation spread sheet
after you know the required KVAR, you must select the the capacitor sizes ,numbers and steps but you must defierntiate between electrical steps and the phisycal steps which i will explain it in a new reply.sorry , i must leave now.