Hi Sundance,
Re-fill by the rocker cover, is that really necessary?
what do you think of using a Molyslip engine cleaner additive prior to the oil change?
Sundance is right. Use the oil filler cap on the cam cover. You'll be there all day trying to pour 4+litres of oil through the top-up next to the coolant tank.
Don't know about additives but the first time I changed the oil on my car, I did run a can of sacrificial cheapo 10W40 semi through before a quick run as a sort of flushing oil.
I agree with the others regarding adding oil but only if I have the engine cover off for another reason, it doesn't take that long just need to be patient.
I've done oil changes through the main filler on the engine, and through the top-up filler.
The top-up route does take longer - about 15/20mins of pouring in slowly through a funnel - but then it takes that long to get everything out of the way and the engine cover off ...so not much difference really.