Refill ATF after a leak

Hey guys, first time working on my transmission and didn’t see another thread quite like this so thought I’d ask.
My cooling line leaked the other day without me noticing and I’m not sure how much fluid was lost. I’m assuming a lot by the pool in my skid plate and the pressure it was gushing out at from a rust hole in the line (part #32907A) (truck made it home fine without any sign of issues but slipped a little when I put it in reverse to move it out of the garage ) anyways most guides say to record the amount drained when you go to change the fluid which is now impossible. I’m wondering if in this case I’d need to get it flushed or if I can just fill until the overflow tells me to stop then cycle it and rinse/repeat.
Thanks!

 

No need to measure.

Do a drain and fill, start fresh, buy 5 qts, put in 4 and let it trickle out using the guide.

 

Awesome, thanks!