Scirocco Register

Any tips for replacing this without dropping or lifting the engine?

Feels like it's in there pretty good, but i'd like to give it a tap with a socket to be sure, but haven't got enough room.

If you mean this seal, remove the 2 bolts holding the cover/holder (the bit in the picture with the seal and 2 bolts holding it onto the block) and slide it off the shaft (be careful not to lose the woodruff key when you remove the cog) replace seal by smearing a little engine oil over the seal and put it in the metal cover/holder then more oil on the shaft and slide it back on the shaft, do up the bolts and it's done.
There should be no need to drop or lift the engine, the one in the picture I did with the engine out of the car but I've changed the seal twice on 2 different engines with it in the car.