Putting things back together, what's the trick with this panel?

[WhipE350]

I just finished my IMS/RMS/Clutch/Oil file tube/AOS and am putting things back together. A year ago when I did my transmission fluid I noticed the support panel (see pic) was not easy to get back on. The car has been on jack stands for 10 days and I'm sure stuff has moved a bit, the panel is even harder if not impossible to get back on this time. Instead of forcing it I figured I'd ask for suggestions. Do I need to lift the rear suspension a little or something else....any ideas would be great!