The mains cable that enters the unit between the lights and the switch will hold it in place, push it into the unit this will allow the base to pull off. there is nothing else holfing it in place except the 6 screws on the bottom. Push the mains cable in and lever the base off, Trust me it will go, the 2 led lights might pop out their holder but they push in ,just make suere you get them the correct way round. There is not alot of servicable parts in this unit, if the heater unit goes it's really an uneconomical repair because thay are almost immposible top get and quite expensive. The manufacturer buys them in bulk so can get them cheap enough, but buying 1 is expensive. good luck
Seamus Monaghan. SIMTECH repairs
February 2010