Hello, I am having a hard time trying to remove.

Hello, I am having a hard time trying to remove the front driveshaft of my 4x4 truck to replace the rear main seal. I have removed the clamps at the yokes at the transfer case end and the front differential but I cannot compress the shaft far enough to remove it. I've tried using a prybar and using a rubber mallet, but to no avail. Will I need to remove the universal joint first? And also, is the rear of the shaft removed by seperating the two yoke halves or is it splined into the transfer case like the rear driveshaft?