What's some of the steps that I will have to take?
Step 1) Sell your current car.
Step 2) Buy a V8.
This is the cheapest, most reliable, and quickest way to get a V8.
The other way (buying and changing engines, gearboxes, computers, labour costs, engineer approvals, and inevitable engine conversion issues such as reliability, insurance and registration headaches), will be far more expensive, time consuming, and no where near as reliable.
The only time you want to put yourself through an engine conversion is when you are doing one of a kind engine work (forged pistons, turbo conversion etc).
When you can get what you want from factory second hand for not much more than it would cost to sell your car, you need to shelve any attachments you have to your current car and bite the bullet to sell.
So to answer your next questions on "how hard" and how "pricey" it would be....
VERY is your answer.
We get this question once or twice a year here on this forum, and for once I wanted to take the time to explain why people like you wont get what you want.
It's just not worth it mate. Seriously.
