Converted mine a few weeks ago. Floor all stays the same unless you go with a non-D20 transfer case.
Shifter is an issue, but sounds like you have a column shifter covered. Only other thing is what to do with the clutch pedal. You will need something to block the hole from the clutch linkage, and either find an auto pedal assembly or find some other way of dealing with the extra pedal. Have heard of just removing it from the assembly, cutting it off, welding it down for options.
Mine still there, have not decided yet.
Fairly easy swap as long as you have all the pieces.