|I usually do the following:
Unbolt the converter first and push into the trans as far as you can (usually an 1/8" - 1/4").
Assuming everthing else is unhooked and undone, unbolt the trans and lower the trans/converter together.
Pull the converter out of the trans...usually this is made easier by pulling straight out and either rocking the converter CW/CCW or spinning it as you pull. There may be a little fluid spillage, but not much (best also, weight-wise if you pre-drain the pan).
TAKE THIS OPPORTUNITY TO INSTALL A NEW FRONT SEAL!!!!! Its a new converter hub and it needs to ride in a NEW SEAL. In fact, never leave a converter installed into a new seal, unsupported, for an extended period of time (ie over- night). This can distort the seal just enough to cause leaks later.
Pour a quart or so of tranny fluid into the converter (through the hub) and insert the converter onto the input shaft and into the trans. Do not forget to wipe a little ATF onto the hub before insertion and a little rocking or spinning of the converter will also help insertion. Be careful not to damage the seal!
While inserting the converter, continue to spin it and push it into the trans until you feel it engage with the pump and it won't go in any further. You will know you have done this correctly when you replace the trans because again there should be a little clearance between the converter and flexplate when the trans is in.
With the trans now in, push the converter back out to meet the flexplate and bolt it all up.
Hope this helps.....others may have additional helpful hints.