Got the same plan lined up for this spring.
Sucking from the reserve only allows replacing 1 or 2 oz. Also will not circulate well enough with the old fluid anyway in case we'd attempt multiple small replacements.
Scrap yard test showed me that disconnecting the low pressure line in the passenger side, then moving steering side to sides (front wheels lifted) will pump dark fluid out easily. Might want to block pump side of that line and refill clean fluid from the top while doing this to minimize air entry in the system.