By breather box I'm assuming you mean the oil separator that sits below the flame trap? If the flame trap and associated hoses were clogged I would assume the separator is clogged or gummed up as well. Hell, I've had problems with pil separators that didn't even appear to be clogged. In any case, if you are going to remove and replace or clean one set of items you might as well do the whole thing, especially when the parts have teh capacity for really screwing up your engine.

As for replacing the oil separator, this is a VERY simple job that only looks complex. All you need is a socket wrench with a long arm to reach down between the intake manifold and unscrew the two bolts that hold the oil separator in (after you remove the flame trap of course... much easier on my turbu without the flame trap). Once you get it unbolte dthe unit slides up and out very easily. I find the best way to get the old one out without a mess is to lift it up, push it back towards the firewall, and drop it down through onto the ground... no drips except on the block. Once its off you should carefully clean the surface with a paper towel, making sure you don't knock any sand or grudu down the hose into the pan. The new unit should slide right in, and once its bolted down you are good to go.

The biggest risk people talk about is knocking the drip down hose down into the pan. However, the hose has a lip on the top edge of it that makes this highly unlikely... if you rammed that sucker in then yeah, maybe you'd knock the hose in, but the oil separator has almost no resistance against the sides of the hose. The seal between the oil separator and the block is formed by the o-ring that slips around the 1" nozzle off the bottom of the separator and is "sealed" when you bolt it down... because of this the fit between the hose and that plastic down nipple doesn't have to be tight (making the jonb much simpler).

Anyway, I found it a really simple fix, much easier than just about any other replacement I've made on my brick... not like that damned fuel filter fiasco I had (now THAT'S a PITA). Youc an find new ones online for cheap... under $20 or so. Make sure you buy a new o-ring as well.

good luck,
rt