Remove the drain coc k completely, drain all the oil out, dont worry or confuse yourself about how much came out, your concern should be did all the oil come out, I shall assume you drained it on a level surface, if you are unsure add a little bit of fresh oil while the drain coc k is removed, it should dribble out within a couple of minutes.
The refill to a little less than the specified capacity if its 3.5 litres then fill with 3 litres, wait a few minutes and check the dipstick, if all is well then it will be in the middle of the hatched area or a little less, you can then top up bit by bit to the correct level allowing time for the oil to drain down to the sump each time.
If the dipstick level is implausible then investigate why before adding any more oil or running the engine/
Some other observations:
The flexible pipes that come with the suction kits are coiled in manufacture and transport and will never become straight, as you push them down the twisty dipstick tube they curl up, you cannot feel when they hit the bottom and they either dont reach it or curl up wit the end sitting higher, each way you cannot drain the whole contents.
I use copper brake and fuel pipes, or for my current vehicle which has an odd bore a copper hydraulic pipe, I have to manipulate and form it to get it all the way down and when I think it is there I pull it up and down tapping the bottom of the sup listening for the confirmation noise, then I drain until it makes the milkshake straw slurping noise.
When I replace the filter I use the same rod to drain the bottom of the housing (mine is an inverted filter like most) poking it down the 2 galleries, I get an extra 0.5l out this way and usually end up refilling with the specified quantity although I do it by the dispstick readings as above.
The dipstick when replaced should be pushed down firmly until you see and feel a positive click, if not then the level reading will be incorrect and you will add too much oil, it took me a couple of years before I realised.
Finally only ever take notice of how much oil you have added after being sure that you have fully drained the sump disregard how much you "think" you have drained out, it is irrelevant, use the dipstick for getting the final precise level after confirming that its indication is plausible with regard to how much oil you have put in.