Let me know if this makes no sense at all.
1/4 or 5/16 or 3/8 OR whatever!
Use the largest size that will work. As you need some strength lips to do this.
Stick the nuts in the hole (one at a time)
Scoot the one under the lip, so the other will go in.
Now, scoot them towards the center touching each other.
If you have the 'right size', you will be able to screw a bolt into each nut, it may take some tilting.
Now you have two bolts standing up, opposite of each other, they are anchored inside the hole, in which you may be able tie together (one pulling point) to pry upward/ hook a slide hammer to/modify a puller to grab them.
As long as the nuts are well under the lip, and you pull the bolts evenly, you should get good results
Below is a picture I put together to show someone how to remove a race. This was a "quick assembly". You probably need the same length bolts, more chain. Heavier slide. You will have to brain it to suit, if you try this.
Personally, I would try a helper and a couple of short pry/crow bars and fulcrums if needed on the bolt heads first.
Let us know what happens.
Images (Click to enlarge)
Monday, May 1st, 2017 AT 6:19 PM