Just finished the same job. PITA indeed! I think the Volvo adage of “if it’s difficult, you’re doing it wrong” doesn’t apply here. Maybe because it’s a yamaha engine?
Angle Gear Oil Change Procedure – 2007 V8 Sport
Standard Disclaimer…I’m slight of frame. If you’re built like a linebacker, YMMV with the below. 
Step 0, order some angle gear oil. I ordered 31367237, but Tasca overrode that selection and it was replaced with part number 31259380
Step 1, remove under-engine cover
Step 2, locate drain plug. It’s on the passenger (USA) side of the driveshaft “facing” the rear of the car. E.g. face of the bolt is perpendicular with the driveshaft. It’s bolt #7 in the below image. #4, #5 is where the driveshaft mates up, #2, #9 is where the front passenger axle meets up (LHD / USA Cars)
Step 3, loosen drain plug with 13mm (thirteen) crescent/box wrench and pipe extension for leverage. Mine was very tight. Note: There is NO way to loosen the bolt with a socket. you MUST use a flat crescent/box wrench.
Step 4, use 14mm (fourteen) or 9/16ths” socket on extension (no ratchet needed) to unscrew over the top of the crossmember. 13mm socket will NOT fit due to lack of clearance with the crossmember.
Step 5, (optional) I ended up taking a plunge saw with a metal bit and cutting off the “forked extension” on the cross brace. I see no purpose for it on the V8. Must have been used on another motor (diesel, T6, etc.). Took less than a minute to cut off and yielded significantly more working room.
Step 6, measure out in 100ml increments and mark the side of a receptacle of your choice (I used a 1L plastic salad dressing bottle donated by my recycle bin)
Step 7, get out your Mity-Vac or similar brake bleed type tool. The smaller hose you can get for this, the better as the inside of the angle gear does NOT have an open path for the tube to follow. I Used some household drinking straws from the kitchen stuffed down in the end of my mity-vac tube to get down in the depths of the angle gear. only problem is that under suction, the straw collapses. Got about 400ml out, plus spillage.
Step 8, Put 500ml back in (or however much you took out plus a bit more, not knowing if it was down on volume or not. just as I put the last squeeze on the mity-vac, it started to drip out the opening, so figure calc was about right.
Step 9, with a dripping plug opening, use magic/the force/the will of Odin to get the plug back in and started. (make sure your old crush washer, or ideally, a new one, is still in place)
Step 10, finger tighten using the reverse of step 4.
Step 11, tighten using your best judgement using the reverse of step 3. No chance of getting a torque wrench on this baby, don’t even bother.
Step 12, Beeeeer
Step 13, Post on Swedespeed
