UKPassats

hi there,i own a 1998 110bhp 19tdi passat,car was hard to start due to fuel pump not working properly and ive bought a second hand fuel pump,and gonna also change timing belt and tensioners.i know how to set cam and pump etc but ive been told that ontop of the gearbox theres a small bung,which you can see abit of the flywheel through,can any1 tell me whats on the flywheel to make sure you got everything set accordinly,ie is there a mark of some sort on it,a hole,this is the only thing im not sure about,any help would be greatly apprecaited or better still even some sort of a picture would be great,