Transmission is out and on the floor. All the guides I found were for the 450 model and the 451 transmission is a bit different on mounting bolts, brackets, jack points etc.
The dog bone and top right mount will help hold the motor. You can support the bottom of the motor right at the bellhousing split and dog bone mount. Good heavy metal there as a jack point. There is plenty of play and movement on the motor.
Then support the transmission on a transmission jack, diy platform jack, or what I used was a motorcycle platform jack.
Then you can play with the motor and transmission movement to crack it open. Pull as straight as possible towards driver side to pull it off the alignment studs. You do have to play a bit and angle the motor and tranny downwards to get it clear. If I had known how light it was, I would have just laid underneath and pulled it. I used the platform jack to help catch it since I wasn't sure of the weight
One little tip.
I for the life of me couldnt figure out how to remove the shifter linkage cable. Turns out that little sucker pops off a ball socket joint. The white plastic collar is spring loaded just push the collar up like an air chuck attachment and pull the whole assembly up and out of the u bracket it sits in.
In my case here the release bearing and arm are busted. Just like the guys video one page back. My bearing is broken off the release arm and the arm has a ton of play. Im fairly sure that is the cause of my issues.
Strange thing is, mine still shifted smooth and drove.