I got a saturn motor unseized before, it was seized due to lack of oil...
take out the plugs and dump atf down the cylinders and remove the oil cap and dump it in the oil pan too... THEN LET IT SIT FOR A WHILE...
then take a big ass breaker bar with a BIG ASS PIPE, and slowly try and turn the crank back and forth
PATIENCE is key if you want it to run again... if you just force it you're gonna break shit... and the motor will prob start going bad very soon afterward from the stress...
they say the water pump will go, oil pump, pretty much every moving part gets fucked from the stress...
so dump the atf in and let it sit for a day or two...
i got lucky and the motor actually ran without smoking or knocking or pinging...
expect it to smoke like a mother fucker when it first starts up due to all the atf, but drive it or let it run and it will prob clear up...
best of luck...
and also, if you get it moving, just keep going back and forth, and be patient... once you get it to turn over a complete 360 degrees then hit the key... and see if the starter will spin the motor over, WITHOUT THE PLUGS IN... and please make sure you use a rag or at least close the hood cause if the motor will turn over it WILL spray atf everywhere... but at least everything looks shiny when you wipe it off lol
i hit the key a few times and it was still binding and bogging but thankfully it kept spinning over very slowly and finally started...