depending which route you take it ranges from as easy as "almost plug and go" to 30 mins - a couple hours work, setting everything up the first time.
if you buy the Astro-eq box and use standard motors you just plug it in to computer, choose your drivers and away you go.
if you build it yourself, you have to source the components, chose what motors you want to use, make your own brackets etc, and then chose the drivers to match the motors and other options you have chosen and away you go.
all depends how handy you are.
They supply the information for almost all known combinations of motors and gearing you could think of. So Once you have decided you just upload the specs to your control box connect it all to together and that is it.
the web site and forum give pretty good and clear instructions.
Once you have it set up the first time, thats it, no need to worry about it. I went the "plug n play route" i.e i bought the ready built box, standard motor kit and was up and running in 10 mins. however the standard motor kit is a "slow slew" option. better to use nema 14 or 17 motors and make your own mounts and belt connections. Which depending how handy you are takes a little longer.