advice on sucking oil out with sucker pump?

I overfilled by GMC 2500 van's A/T so I ordered one of these to suck out about a quart of ATF.
https://www.amazon.com/gp/product/B00GW3QM4C/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Problem is the dipstick for the Tranny on a big van is about 6ft long (!) so I guess I'll need to buy a length of vinyl tubing at local hardware store.

Anything else I should know?

I was thinking of doing ATF flushes and filter change on a couple of cars but maybe I'll just use the pump to do partial changes. Most of the cheap $20 electric 12V pumps have iffy reviews and I can't tell if 1/3 of the users tried to suck oil from 5ft dipstick tubes with 4ft supplied hoses. Anyone had good luck with cheap electric sucker pumps? Link?

 

Just use a manual sucker