I'm trying to decide whether this would be a good time to learn how to
solder copper pipes. Here's the scenario:

Point your forefingers at each other, similar to the way they'd end up if
they were stuck into one of those Chinese handcuffs kids get at birthday
parties. Now, move them apart about a foot. They represent two 3/4" pipes
facing each other, on the basement ceiling. Right now, that gap between them
is occupied by a water pressure regulator I need to replace. The regulator
has female fittings molded into its housing, and the pipes have male
fittings. The pipes continue UNINTERRUPTED for 10 feet on either side, so
I'm guessing the pipes were not rotated into the regulator. Rather, I think
the regulator's female fittings may be threaded in such a way that rotating
the whole regulator tightens both sides at once.

Or: the male pipe fittings, which are separate pieces from the pipes
themselves, were cranked into place, and then those fittings were welded to
the pipes.

Based on what I see, anything that would need to be soldered is plenty far
away from anything heat sensitive, like beams, wires, etc.

My question (which requires psychic powers to answer):

On a "trickiness for beginners" scale of 1 (easy) to 10 (check your flood
insurance), where does it sound like this job falls? A 3x margin of error is
acceptable for all guesses, and horror stories are more than welcome. Bring
it on!