Astro Van sliding door came off tracks. Advice please?

[Funk-O-Meter]

The first time It came off and I was able to twist the pivoting wheel assembly, tuck it inside and slam the door in and it stayed. I wasn't able to get it to a mechanic or fix it myself and it got opened by mistake last night and I can't get it back on the tracks or closed. The small wheels are a little chewed up but looks like they should still work if I could just get them back on the tracks.

Anybody?

[Blue Bowtie]

The lower arm does all the support. The outer arm and top (interior) arm are basically only guides. You may have to adjust the lower arm position.