I'm changing trans fluid on my 2006 e-Hydro Deere 4320, but I cannot remove the 'elbow' between the transmission and the pipe to the oil filter. (400 hrs, it doesn't get a lot of use but I enjoy it.)

Deere book says to remove this elbow to get at the suction screen for cleaning.

I removed the 2x 12mm cap screws, but I cannot get the elbow loose. It looks like the pipe between the elbow and the large trans. oil filter is swaged on, both ends, and I cannot get it loose.

I tried tapping the elbow with a wood mallet and it loosens but does not come free, it looks like a collar or somthing extends beyond the elbow transmission side flange and into the trans. Book shows only an O-ring.

Does anyone know how to safely remove this elbow?