They leadscrew should go out and in to the leadnut no problem, if you have a taper turning attachment type thingy the leadscrew needs to be disconnected regularly.
For general maintenance as well it should be a doddle, screw it out, pull the slide off the saddle for maintenance, then slip it all back together again.
As mentioned, slacken up all your adjustments and it should pop right back in, making sure your gib strip is the right way round/fitted correctly(some have locating dimples).