Be sure to leave enough extra length to get the pipe cutter behind the ferrule, and then some. Probably the best way to go. One alternative is if you can find the plastic cover plates (chrome look) with the split in them. Most big box stores don't carry them, but some hardware stores do. (They look and work great and are not to be confused with the split metal ones that look too raw and industrial.) That way you could remove the valve, leave the nut on there, and install the plastic split cover plate (w/ chrome look) afterward.

I realize that this is an old thread but I want to respond for anyone with a similar problem in the future. I am amazed that someone would tell you to hire a licensed plumber for such an incredibly easy job. Come on, folks! Have we become so helpless? When I read the question, I assumed it was about copper or galvanized pipe which would be very easy to fix too but then I saw it's PVC pipe. Nothing could be easier to fix and I have no idea why the person asking the question thinks he cannot remove the elbow. Of course you can remove it! You can simply cut it out with a hacksaw and put in a new elbow. You can extend the pipe that is cut off easily with just a union and a piece of PVC. Working with PVC is so incredibly easy that I am baffled about why the question was even asked. A proper repair would take about ten minutes and cost a couple dollars. I never cease to be amazed by how helpless people are becoming. This is pretty sad.

I have a unit in a high rise condominium which has banned the use of plastic tubing to a compression fitting from a fixture to the fixture stop value. I imagine it is because of incidents like I have experienced with a 3 story house (described below). Particularly insidious is the tendency to develop a very small leak which isn't detected in the room where the fixture is located because it is too small and leaks into the wall cavity causing damages far removed from the source of the leak which make it hard to locate the source. I am in the processing of cleaning up the mess from a long continuing and until recently not discovered leak from one of these connections from a sink fixture (hot water side) on the 3rd floor of a 3 story house with basement. Apparently for years, there was a slow drop, too slow and limited to be noticed as the water just seeped into the wall behind the fixture. On the first floor there was a bulge in the wall (interior) below the indoor unit of a mini-split system install near the ceiling, so some evidence of water where it shouldn't be, but, I suspect the lines from the mini-system and it didn't seem worth tearing open the wall to investigate. Over time (years) the leak seems to have increased and I found water accumulated in the basement floor (concrete) near where the boilers, hot water heater and water softener were located. I suspected first the hot water heater (so shut if off at the water inlet), then the water softener discharge as the floor drain had blocked. The water heater was turned back on. Possibly the surge of water in the lines (as often happens when water has been off for a long time) may have cause a water hammer effect which increased the leakage. In the end, I with a second floor ceiling collapsed exposing the underside of the third floor, I could see that it was a plumbing leak. It still took some time to find the bathroom (there were two above the ceiling with the problem because there was never a trace of water on the bathroom floor. All the water had leaked into the back of the cabinet at the seam between the cabinet bottom shelf and the cabinet back wall and from there into the wall. That was the most troublesome thing about the leak. It just wasn't noticeable until the ceiling collapsed. The most obvious suspect, the mini-split system located just above where the damage was initially evident had nothing at all to do with the leak.

I would discourage the use of compression fittings. They are the weakest type to use in that application. Typically used by only the wham-bam homebuilders, as they are quick and easy for illegal immigrant faux-plumbers to install. A family member bought a fairly upscale (built mid-90s) townhouse which was plumbed with compression fitted supply stops. When the time came for a DIY swap out of some toilet tank guts, the valve spun right off the pipe! This created quite the flood while he scrambled downstairs, out the door, and fumbled around in the bushes--in the dark, nach--for the main shutoff. As an alternative, I'd suggest sweating on a male (MIPS) nipple, then wrapping it in teflon tape and torqueing on a FIPS-fitted supply stop. A nipple is a single, simple joint to sweat solder, even with limited torch skills (as contrasted with a tee, for instance). Plus you can look right inside the nipple and see if there's a silver ring of solder completely around the perimeter of the pipe-end, which is a good indication of a properly "filled" joint. I see at least 2 problems with that DIY site: 1) Teflon tape or dope on the end of the pipe? WTH? This shows a lack of understanding of how the pipe deforms and seals to the ferrule, and how the ferrule seals to the funneled housing. Tape could possibly interfere with that. Just let the carefully formulated metals do their metal-on-metal thing. Plus the metal-on-metal squeaking becomes a good indicator of having tightened enough, and discourages OVER-tightening. 2) As pointed out by Formula1, it's VERY important that you use a 2nd wrench to apply COUNTER-torque to the valve body (which has wrench flats for just that), such that the pipe itself experiences close to zero torsion. Failing to do that could collapse the pipe itself, or even compromise the ell-joint inside the wall!