Octy2 Elegance estate - Amp + fronts how big a job?

My new elegance estate has the stream MP3 head unit which although nothing special is good enough not to change it (yet). Have to say the tweeters on the fronts are too loud and sound more like a tinny speaker than a proper tweeter to me.

I fitted a new HU, amp and front components in my previous car and ended up pulling off lots of trim to run cables. I'd had the car 6 years when I did it, so it wasn't as stressful as it might be on a new car!

I removed the system before I traded the car in so I have a 5 channel Pioneer amp and a sub. I left the infinity components in place as I thought it unlikely they would fit - but reading here I think they might have done D'oh!

Components were the best single upgrade so I might just change the fronts as a first step - if I can work out how to get the door cards off.

Anyway long story short... if I do tackle the amp install how removal friendly are all the trims etc that will have to come off to run the cables?