Unwise the 4 bolts behind the drums and remove them with bearing and centre spindle, service your brake and depress the bearing holding centre spindle through hydraulic press, the spindle (Bearing) and drum will left eachother.
as the oil is drained completely while replacing the chain ad after the new onw is installed< according to the manual approx 3.8 liter oil must be poured for ist time, have you npticed that.....
I have nissan micra k12 with CR14DE engine. its a flying ,machine but there is a little problem that on cold start< the engine rattles till idle RPM, after that it become fine....