Its like most people have never dealt with such before. But am assuming that the process will be just like the due process followed when acquiring an apartment. Just be cautious with your money and use trusted legal representatives, have your lawyers as well. Do not let the seller dupe you into accepting that you use his/her lawyers alone.
But why do you intend to invest in an office space? Already the demand for office space is at a plateau stage, where no new demand is recorded. With the completion of the few skyscrapers in Westlands and Upperhill, I think the supply of office space will supersede its demand.
Anyway, success in your endeavors.
Enjoy every moment of your life, you never know when your time will come.