Yes, the rear half of the yoke should slide off (forward) of the splined shaft. It may be a bit hard pressed back onto the splines after your disassembly process, so may take a bit of persuasion.
You do have to make sure there is enough clearance between the torque tube ball/shaft/u-joint and rear of the transmission housing to allow the yoke to move forward off the shaft.
You could lower the front of the torque tube with a jack to allow clearance of the transmission housing to remove the yoke and then raise it back into place while you do what needs doing on the u-joint assembly.
Dan
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)