Got myself an oil leak out of the bottom of my rear diff ('88 4x4) is it a big job to get a new gasket put on there (I assume thats the problem) or is it best put to bed with a little gasket weld type stuff?

Is it leaking at the back ie were tin plate is bolted in diff. or is it at the front of the diff. at the prop shaft side?

Sorry didn't think to specify, yes its leaking at the back where the plate is bolted on. Any ideas?

Drain, remove plate, re gasket, fill