tips and tricks that I had to learn..
Did this mod a week or two ago (from scratch i.e. sponsored by random-dude-from-ebay-china, no neo bulbs) and thought I'd share a few things I learned, for those hardcore DIYers that would rather do it themselves than take up emelianenkov's generous service (his price for labor is really worth it if you're not extremely patient).
You have to figure out which way the contacts go, because the LEDs care. That was an annoying trial/error process for me for a few hours, especially for the twist-on bulbs in the HVAC.
Speaking of the HVAC, if you have bulb sockets like the OP, all is good and well, but if you have this different kind, or bought replacements from the stealership like me (before thinking of doing this), there's a different kind of plastic piece on some of those that has a small metal plate on either side for contact, instead of the grooves for wrapping the wire.. I found the best way to go about this was just to spend some time with a knife and pop off the plates (so I could take out the OEM bulbs), and then kind of cut my own grooves in the plastic to wrap the wires around, as getting those plates back on is worthy of many expletives.
Speaking again of the HVAC, my experience with twisting them back on was painful as well; I almost stripped them with the flat-head screwdriver, and ended up having to disassemble the plastic covers off each of the parts of the HVAC until I got to the circuit board, so that I could get a grip around the side of the bulb assemblies with some needlenose pliers.
Speaking once more of the HVAC, contrary to OP's suggestion perhaps (unless I misunderstood?) it was better lighting and less hotspottyness to point the two LEDs that are behind the LCD directly at it, rather than at some angle. If you're changing out the bulbs that light the OEM switches, however, I would recommend figuring out which way they angle so that it points at the switch button when you lock it in; these are ok without that care taken, but dimmer than they could be.
Last note on the HVAC, I swear. The two bulbs that light the LCD (those two only, nothing else that seems "in-line" with them such as the one that lights the reset and mode lights) run on 6v rather than 12v power, as mentioned before. For 12v power, a 1.2K Ohm resistor is fine, but for those two 6v bulbs, get some resistors in the 300 Ohm range (I used 330) for something that looks to be about the same brightness as everything around it. Especially important if you're doing the LCD reverse polarization as I did.
And if you're embarking on changing out the LEDs in the stereo, I'm sure that the PLCC2 LEDs will kind of work, if you're ridiculously careful, but I just got a T1808, which looks pretty darn similar on the circuit board to the factory stereo, and right after changing out all the tiny LEDs on that board for some of the spare PLCC2s I have, I put the plastic faceplate back on and screwing on all the fastening points made some crunching noises that sounded exactly like solder cracking and separating LED from board; I also heard a piece of something bouncing around in there after that :dammit:. The problem is that the PLCC2s are about 8x the size of the LEDs on the stereo. Therefore, for the stereo use instead 0603 SMD LEDs which are (I have been told) the exact size of the ones originally on the circuit board on a fresh factory stereo.
By the way, if the OP or others here didn't mention, for free-standing LEDs (just a bulb and wires) the longer one is the anode and the shorter one is the cathode; also if you look at the bulb top-down (wires pointing away from you) you'll notice that the round rim at the base of the bulb is flattened out on one side; this is the cathode side. On PLCC2s, the cathode is on the same side as the key corner of the LED, which, if you imagine the light-outputting part of the LED as a spa/jacuzzi, looks like a step you might use to get out. I like to think of it as an arrow pointing in the direction of current's flow. Lastly for 0603 LEDs, if you look really close at the top, you'll notice a distinct dot closer to one side or the other. The dot side is the cathode side.
The anode gets the positive side and the cathode gets the negative/ground. The LED (by design of a diode) won't work if you switch this, that's why I'm so excessively specific.
For those who don't do soldering much, it's best to tin the LED's contacts as well as the circuit board's pads (enough, not too much) so that you can kind of just lay the LED down and melt the solder together.
Hopefully that wasn't all "duh" stuff and I helped someone :]