Yesterday driving arround my town i found an old toyota hilux practicaly destroyed, but it has the front (ifs) and rear (solid) axles there, a closer look revealed that the front discs where vented with two pistons and the rear diff was much bigger. the engine wasnt there but i think that used to be a 2.4 diesel in there, because the rear axle was big but no so big as the diff on the 4Runner

 

now in to the questions:

Can the discs and the rear axle suit the corolla?

how hard will it be?

Yes if you have a welder and a grinder are are prepared to use them.

you can use the front calipers on the right size disks but you have to get a custom bracket made and you maybe limited to what wheels you can use i.e. 14/15's etc