Very quick question.

I've been busy the past few days so have not sorted my CCT yet. I may have to postpone this further as I don't have a new o-ring or washer for the inspection cap and crankshaft cover and I don't know when they were last changed.
Can I do what is mentioned below without draining the oil?
Just so I know exactly what to do next time, after I have new o-rings and washers.

I need to...
Remove Spark plugs
Remove inspection cap and crankshaft cover cap
Line up the rear cylinder timing mark
Remove the tensioner cap and turn screw clockwise
Release the screw, replace cap with new sealing washer
Turn engine over by rotating crankshaft 720 degrees Clockwise/Anticlockwise?
Replace inspection cap and crankshaft cover cap with new o-ring and washer
Replace Spark plugs
And I'm good to go?

Sorry about going on and on about this. But I'm pretty sure I know what to do now just need a confirmation from somewhere who's knows what they are doing. Thanks.