I'd say someone with some basic skills who is familiar with smt stuff should be able to put together a minimig in about an hour.
I only took me about 5 minutes max to lay down the fpga, and thats the hardest component on the board. As small as the leads may be, you still don't need any magnification or special tools to get it on there.

flux the pads
rake the iron across the pads to build up a layer of solder
center the chip on the pads
tack down two corners
double check the centering
get a tiny solder ball on the tip of the iron, place down the iron at the start of the pad and trace it along the pad until it bumps the lead, you'll see surface tension on the solder work it way up the lead, etc.
For the chip resistors and caps, I smear some paste on both pads and build up a thin layer of solder on both of them. I then center the device on the pad, press down on it and hit one side, then i do the other and then go back and hit the first side again. Actually, I add the solder layer on all the pads for all the device before i start, that way it only takes a few seconds per device to tack them down.