If the trans fluid is still pink and still smells like trans fluid then your good, leave it alone. If its starting to go brown and looses that great trans fluid smell, it's time to change. Changing the filter and fluid by dropping the pan is ok and the way I've always done it up to a few years back. Now they have these pump/machines that run at operating pressure that work like a blood transfusion. The new goes in as the old comes out, replacing ALL the transmission fluid. When you change it by removing the pan, you only get some of the old dirty fluid out. These newer machines do a thorough job and only costs about 100.00 at a brake/muffler shop.

 

Is it the lower line at the radiator that is the feed line on a Blazer LT -97? (4l60e)
So is it just to unbolt it and connect a suitable hose to it and starting to pump the oil out?

And of course re-fill new oil after about 2 quarts as described earlier?

Thanks,

/qsec