Don't know about this particular engine but it's quite common to have restricted access and to have to use a vacuum pump. On the Smart car there isn't even a sump plug any more!!!
http://www.force4.co.uk/859/Force-4-...ctor-Pump.html
There are also heavier duty versions around.
They work very well - remember to warm the engine up first. Of course you still need to change the filter. I also chuck some cheap oil in and suck it out again to do some extra flushing.
If the tube has dropped down or something you may not get accurate dipstick readings any more.