You're trying to get the intermediate shaft off the pinion? If so, two things I've found
- disconnect the I-shaft from the steering wheel. (Tie down the steering wheel first.) This lets the I-shaft rotate on the u-joint. Otherwise, the u-joint collar gets cocked on the pinion shaft, making it hard to get off.
- I split a short piece of 3/4" pipe lengthwise, and clamped the 2 halves around the pinion shaft. Hammering/tapping on this keeps the force on the u-joint collar aligned with the shaft, so (again) the collar doesn't get cocked.
(If you're talking about something else, apologies for the intrusion.)