Never did that job myself but I know there are no internal trans parts
for that car. (At least that was the case in 2008)
"Repairing" a 500 trans at the dealer level involved removing the broken
one and replacing with a brand new one direct from the assembly line.
I went through that rigmarole with a Ford 500 company car that was
2000 miles outside of warranty, with a trans failure. The whole engine
cradle is dropped to do the job. It's a labor-intensive deal and it cost
an arm & a leg.
On your situation, you may be able to get the part, but I'm thinking
you won't easily find any shop manuals detailing an R&R for the flexplate.
As the drill sergeant said, "I taught you everything you know. I didn't teach you everything I know."
"Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so."
- Douglas Adams