They don't want you messing around inside the microwave because it's potentially very dangerous - radiation and very high voltages - they don't want to be dragged into court - it's a c-y-a statement.
You need to take the covers off to access the lamp - make sure power cord pulled and keep clear of any large capacitors if there are any as they might hold a hefty charge even with the cord pulled.
Peccavi, June 2009
