Transmission leaking like a seive

[kw]

I stopped for gas yesterday in preparation of taking the suburban in for an emissions test, which it failed due to NOx.

After fueling up, I noticed oil residue all over the rr window, looked underneath and there's transmission fluid all over the undercarriage. Leak looks to be coming either from the rear of the transmission, or the transfer case. Is this a seal, and can it be replaced without dropping the transmission?

Thanks in advance for any information you can pass along.