You shouldn't have to disconnect the hoses if you need to remove the forks.
Take off the left hand brake cyclinder by moving the locking lever and pulling it off. Remove the wheel and then undo the mounting bolts for the cyclinder on the other side - this is the opposite process of installing the brakes. Be careful not to put tension on the brake pipe - use string or cable ties to tie the cyclindersto somewhere like the handlebars or frame.
Instruction/installation manual can be found here.
I used to have some of those on my old MTB – IMO the best rim brakes ever. I also seem to remember that you shouldn't have to disconnect the hoses, but if I'm wrong and you do, then yes, you'd have to bleed them. And be careful about what fluid because If I remember correctly Maguras use mineral oil (I have Martas on my MTB). I think Magura call it Royal Blood or something comedic like that, but you need to make sure you use the correct fluid. Not sure how easy they are to bleed, as my HS33s never gave me any trouble, but the Martas were a bugger to bleed. My LBS tried twice (and charged me twice) and still couldn't do it. I took it to a proper shop (MountainTRAX in Wokingham) and they did it right first time for half the price and they've been great since.
I was reluctant to do it, never having dealt with hydraulics before, but using the Magura bleeding kit turned out to be quite easy in practice. The Royal Blood (it's blue - geddit?) is benign stuff, unlike some hydraulic fluid. It was obvious when the job was done, because nice blue fluid appeared at the top of the system, displacing old brownish fluid.
It is definitely a good idea to:
1) take the lever off the bars, so that you can hold it high
2) have a helper to hold things - two hands were not enough!