I've read dozens of posts about this, and it seems to make sense, just want to be sure I have it right....

I'll be installing a valve body, filter and new 4x4 pan at the same time...so the process is...

poke and drain stock pan (or just remove and get oil everywhere)
remove pan
install valve body + new filter
install new pan
measure how much fluid I've drained out and add that much fresh fluid
disconnect return line on back of trans (coming from cooler)
start truck, pump old fluid from return line into bucket
watch for how many quarts I'm pumping out at the same time add that much fresh....until I've reached 18 quarts of fresh

Does this sound right? Should I be cycling through the gears while its pumping or does it matter?

I could take it to the dealer but would rather just try and do it myself if I'm already doing the vb and pan....

Thanks

BTW, I only have 29k miles.....the other option is to just do the partial fluid change and wait until 50k or so for full flush.....??