This is based on a 2007 M35. Your vehicle may be slightly different. Some people have done this without removing anything by wriggling their hands inside deep enough to reach the bulb sockets. However, I'm a 6'3" 200 pound rugby player so that method doesn't apply to my hand or arm size. This method removes everything needed to provide complete freedom of movement and takes only a few minutes.
To replace front turn signals, you will need a socket to remove a few bolts, a screwdriver, and a pair of lint-free or latex gloves while handling the actual bulbs.
Begin by removing the right and left side engine covers:
Next, remove the bolts holding the washer fluid tank and the coolant tank. Both of these will remain attached at the bottom. The washer tank simply slides back out of your way and the coolant tank can be lifted out of it's holder and also slides away from the work area:
Next remove the center air intake piece and set it aside with the left and right engine covers:
Now remove the air box by un-plugging the MAF sensor and loosening the air hose to remove it from the back of the air box. After you do this, remove the air filter and grab the air box from the inside - pull up sharply and it pops out of its holder. Set it aside with the rest of the engine covers. Now you have plenty of space to reach both passenger and driver side turn signal sockets.
Always wear latex or other lint-free gloves when you handle any auto bulbs - LED or not. Oils from your skin will decrease the lifespan and you don't want dirt and grease on your new bulbs.
To use LEDs for turn signals you will need a decoder OR a resistor for each bulb to prevent errors on your dash and rapid flashing of the bulbs. I purchased decoders on Ebay for less than $20 - they are plug-N-play so no need to cut into existing wiring. (resistors are much cheaper but you will need to cut into wiring and I wanted a cleaner install). Simply place one end of the decoder into the existing car socket, and place the bulb in the other end of the decoder (like an extention set). Decoders are available for any size LED bulbs except the Vled brand "V3Triton bulbs" which require an old school resistor, or the decoder sold from Vled. When I upgraded my fender turn signals to LEDS, I also used decoders.
Pasenger side bulb installed:
Driver side bulb installed:
Remember! After you install your new bulbs and BEFORE you re-install everything else: TEST the bulbs. Lots of LEDs are 'polar' and you may need to remove and reverse them in their socket to get them to light up.
Also, remove and replace bulbs VERY slowly to prevent loosening them and having them fall out of the socket and into the bulb housing - avoid letting the bulb scrape against the housing while removing and installing as well.
This is another reason why I went to the trouble to remove items that were in my way. If you are twisting your arm and hand to reach the sockets, you increase risks of losing a bulb, or scratching / damaging it.
Once you have verified the bulbs work properly, re-install the air box FIRST by mashing it back into its holder, then slide the intake hose back onto the rear of the air box and tighten the clamp. Re-intsall the MAF plug into the air intake Then re-install the center air intake piece. Then re-install the coolant tank into its holder, and slide the washer tank back into place. Tighten the bolts to secure them.
Now your headlamp housing will have no amber colouring in it when the turn signals are off (using LEDs) but they will light amber when activated.
Hope this helps. My LEDs have been running since last year with no issues. I recommend Vled brand bulbs for all LEDs. You can find their website here:
You can find bulbs cheaper if you like, but I only wanted to do this once so I went with what I feel is the best value and highest quality. As long as you don't go for the V3 Triton series of bulbs, the Vled bulbs aren't very expensive at all.
LEDs should last near the life of your vehicle, draw less power, and are usually brighter than reg bulbs.
They also have crisp, instant on-off firing which makes your turn signals stand out.