I wounder if this is the turbo:

http://home.no/laminatkabinett/turbo.jpg

If not, where can I best replacing the turbo? From downunder the car?

you can just see the turbo from there, If you can get the car up and get under it, it is easier from below. remove the exhaust downpipe and your right on it.

i'd say the superb would be easier to do than a fabia as the engine is the correct way round

This is the turbo circled you will need access to both top and bottom of the car to remove it.

Your egr valve looks in a mess as well tbh.

Yep the oil covered part in the top left is the EGR which is, as pointed out above, knackered.

Don't take this the wrong way but if you can't identify the turbo yourself then it's not something you want to be thinking of taking off.

Your egr valve looks in a mess as well tbh.

Should I change the EGR or do I only have to clean it?

Should I change the EGR or do I only have to clean it?

Clean it, they all get to look like that after 40k, clean the outside in situ and then take it off to give the inside a good blast with carb cleaner or WD40.

Most of the muck is where the oil has been topped up and like most ppl it's been spilled and gone down the cover, notice all the crap around the filler hole as well, you'll know if it's knackered, it'll be making knocking noises.