Okay managed to get the bearing off and I have progressed to the stage where I put the front housing on and have encountered a few more things...

1- When I put the diff shaft in and then the front housing on so its flush with the main casing (without bolts yet), I can turn the shaft and it move smoothly. However, once I bolt it up and to the correct torque, the shaft doesn't turn very well, its choppy and it feels like something is not right inside the differential...Is this correct at this stage? Is it meant to do this?

2- In an amateur move, I mixed up the balls for the selector shafts. One is small and one big? Which shaft is which ball for?

Thanks for your help!