It all depends on your setup - if it is well set up to be run on skeleton crew then it is easy, if it is not, then it can be a pain in the rear end.
Some basic tips:
* If you are running off of a 2 scene preset desk - check to see if it has a grab master. That will allow you to preset 2 scenes in advance - it takes a while to get the hang of it, but it basically works like this (I call the presets red and yellow, so bare with me). Set Red for LX1, Set Yellow for LX2. Red master up on LX1, hit the record button for the grab master, bring it up, bring down red, set red for LX3. On LX2, bring down Grab master whilst bringing up yellow master, hit the grab master record, and bring the Grab master up, then drop the yellow master and set yellow for LX4. Some desks come with two grab masters - I usually just use Grab Master 2 for a houselight preset for emergencies etc.
* Try to preset sound as much as possible. Many desks have Mute Groups which is great when a lot of your sound cues are for mics - so basically if in scene 1, actors 1->4 are on stage, whilst 5->10 are off stage, then scene 2, actors 1,2,4,6,8 are on stage the rest off etc, you set up the mute groups accordingly, then it takes one button press to change between mics 1->4 on to 1,2,4,6,8 on only.
* If you have lots of audio - make sure it has been mastered correctly - if not, see if you can get it remastered. Basically, you want to be able to hit play for each cue instead of hit play as well as ride the faders.
* Set up your work area well. I learnt that really quickly when I did my first few corporate gigs - where you often have 2+ laptops, 2 DVD players, cue monitors and a switcher for vision, plus sound desk, LX desk and a prompt script, along with odd things like voting interfaces or autocue controls, and usually only one operator.