Actually, there is a way to do it without dropping the pan.
Keep in mind that the difference with shifting mechanisms (Column vs Floor) on the transmission has to do with the external lever on the transmission. On Column Shift Transmissions, the lever points down while on Floor Shift transmission, it points up. To correct this issue, you normally have to tear the transmission down and reverse the lever.
TCI makes a shift lever that mounts to the outside which takes care of that problem without tearing into the transmission. On my Column shift C6 transmission, I purchased the part from a local Speed Shop for $24.99, not including tax back in 2004. The Shop is now out of business but I would imagine that it is still available. The Part Number on the receipt is #27316. I am not sure if this is the TCI number or not.
Hope this helps.
BT