Advice please - how easy is a diesel head gasket replacement?

[thegoodman]

I have a 92 Corolla 2 litre diesel estate, japanese import - it's hardly worth $300. It's still running but the head gasket has gone and it loses a litre of coolant every hour or so. The garage wants $800 to do the work so I thought I'd do it myself. Do you think I should? How easy is it? Do I need loads of specialist tools? Just wanted someone's opinion really. Thanks

[Flashmn]

If you have to ask those questions, you better have the garage do it.