I would suggest something similar to how the Gallowgate Twins in Glasgow's East End were brought down (dismantled piece by piece) in 2015-16, but they were a completely different kettle of fish. They weren't severely fire-damaged for one thing, nor were they directly attached to a railway station (they did loom right over the North Clyde Line though, which was partly why they weren't imploded like the Red Road towers a few miles to the north were). Whatever method is chosen, it will doubtlessly be an even more painstaking job than the Twins.
About a decade overdue imho. The owner clearly wasn't going to do much with it apart from letting it rot while blowing off any attempts the council made at communication. Enough is enough, put the thing out of it's misery already.
No doubt this is going to happen now, but this 'split milk' has been a complete, utter and increasingly dangerous farce. It's frankly a miracle no-one was injured here.
As noted above, something like this would require cooperation between South Ayrshire Council, ScotRail, Network Rail, Transport Scotland and the local bus operators (primarily Stagecoach), to say nothing of raising the finances for such a project. I would like to see something like this happen for the same reasons (moving on from this sorry mess, replacing that dive of a bus station etc), but I'm not holding my breath.
Nine months to over a year is what I'm thinking is going to happen here. Any eariler reopening date is just hopeless optimism at this point. That this is now necessary is utterly shambolic, but nowt else to do now but grit one's teeth and endure it. I would like to think lessons will be learned from this, but the cynic in me highly doubts it.