If you have never removed a M103 transmission before then removing it with very little clearance room is a difficult proposition. It's obvioulsy a much easier job on a hoist. Even then long extensions and a breaker bar are required for the top bell housing bolts.

It's even more difficult to align the torque converter with the engine and get it connected with limited access room - if you are a newbie at this.

Try to remove both engine and transmission.