How easy it is to disconnect existing hydraulic brake lever and plug in another lever

[echappist]

I guess the real question is, "is this a rather technical job best left to the pros?"

I have a MTB for which i may want to convert into a road-ish set up (currently has Avid hydraulic brake levers). Also have another bike currently set up with 105 for which i may want to install Di2.

On caliper systems, i'd just take out the cable from the housing, swap the brake lever (or shifter), and I'm good to go. I'd imagine the process to be more difficult, if actual hydraulic line work (e.g. bleeding of the line) is required. Anyone cares to enlighten me on this?

Thanks,