At some point you're probably going to have to remove a fine threaded fitting.
Even if you're not hands-on, you may be stuck with the job due to circumstances beyond your control, commonly known as "boating."
Exceptionally fine threads seem to be used in the most strategic of circumstances, meaning if you strip them you're really screwed, pun intended. Typically you run into this problem on a diesel, and it's usually on the very high pressure injector pipes where they mate to the injector or the injector pump. Once you free two such fittings they're going to be difficult to rethread, particularly, as with diesel fuel pipes, if they're misaligned. And you're almost sure to misalign them at least a little if you need to bend the pipe back to separate the fitting. Avoid bending that pipe at all costs, even if it means disconnecting at both ends to avoid the bend. Better still, avoid completely unscrewing the threads. Typically this issue arises if you're bleeding your diesel, but you don't need to completely unthread the connection to accomplish the bleeding. But if you're not careful, you'll strip those threads when you're trying to re-mate them and end up spending a lot of money.
To get your parts rejoined, don't try to screw one part on to the other. Screw it OFF the other. Make sure your surroundings are quiet. Mate the two parts carefully, have the threads touching, press them together gently, and unscrew part A from part B as you press it toward part B. Listen closely. When you hear the threads quietly click it'll mean that they're probably just in place to mate and then, without reorienting the parts, start screwing the fitting on with fingers only. This is a precise operation, but if you do it carefully it can save a lot of time and perhaps a lot of money