I did an avenir swap in a day. I spent a year lowballing the parts though. I had 4 people helping me part of the time. I also had a lift, a welder, over 100k in tools combined, parts washers, torch, etc....
no it was not running perfectly after that.... but the next day it was....
we had to completly fabricate the intercooler piping too... didn't have anything to weld aluminum with so it kinda looked like butt....
getting in a hurry will only cause problems, asking a professional shop to do it will only cost more than the car is worth....
don't even think about doing it if it's the only car you have access to...