There is not a chance I'd be drilling new 'oil' drip holes in the bottom of my Ferrari's engine!!! I've done the oil before during intermediate oil changes between putting the car in for its main dealer services, I actually found it quite theraputic... although I wouldnt feel that way if I did it often!! LoL
On the 360 (different to the 355 but essentially the same basic engine) I changed the oil myself @ intermediate steps and it wasnt rocket science, yes there are 2 sump hex nuts, both different sizes just to be awkward (thank Ferrari!). From the onwers manual (and as fitted by Ferrari) the Engine takes just under 10 litres of Shell Helix Ultra (yes the expensive stuff!), read the owners manual. A PDF is available for free download on the official Ferrari owners website if you care to register...
The biggest pain in the job is removing the underbody tray to get at the nuts and I alslo removed the top aluminium engine cross brace so I could get access to the oil filter, I used an oil filter chain to remove it. Dont forget there is also a small pull out mesh filter (with 2 10mm hex nuts on) which can also be removed and preferably cleaned. Its referred to in the workshop manuals (suggesting compressed air to clean it!) but I wonder how many mechanics actually bother?
Overall its not hard but the first time you try it, it will take a few hours for someone without previous experience (at least on the 360, much will be the same across 355/360). I remember it took me about 4 hours my first time but I didnt want to screw it up so I took my time.
Also word of warning DO NOT OVERFILL, it can cause the engine to smoke. The way I did my measuing was to put the used oil into a measuring jug hence knowing how much I'd removed allowed me to approximate how much to refill (its not easy to get an accurate reading on a dry sump engine, you must let the engine warm up and measure it straight after turning the engine off or while running - again see owners manual for exact approach).