Autobox service

1992 1.6 auto

Hey...seeking advice on changing the ATF in my box - it's brown, smells fine and shifts ok....but I've no evidence of it ever being changed and it's meant to be red right?!  I'm also too broke to pay someone to do it, am pretty reasonable with spanners, there are no specialists nearby, blah blah.

My understanding is that the book way of doing it is to drop the sump off entirely, ruin the driveway due to lack of drain hole, pull the pipes to the cooler, refill through the dipstick hole and get some into the cooler by blowing through a straw or something....

I have a pela pump and hoses to fit down the dipstick hole.

So....if I were to get it nice and warm and then suck it out and refill, possibly adding a can of magic gearbox cleaner.....ran it around for a month, repeated, and then did the same a 3rd time....skipping any magic cleaner on 2 and 3....this would essentially change my ATF without ruining a driveway, my back or anything else?

Also, up until things got all newfangled and electronic, ATF is ATF right?  I'm familiar with changing it in marine gearboxes (hence the pela pump).  Comma/Miller/whoever will be fine?  

Thanks