A five-minute walk away the rebels have turned - meaning

Question

Source: http://news.yahoo.com/confusion-over-rival-claims-control-donetsk-185927751.html

Unfortunately for Taruta -- a billionaire oligarch appointed by Kiev to run the restive region following the ouster of pro-Kremlin president Viktor Yanukovych in February -- he was being forced to talk to journalists from a meeting room in a luxury hotel.

A five-minute walk away the rebels have turned what should be his office on the top floor of the region's barricaded administration building into the headquarters of their self-declared state.

I don't understand what this part means: a five-minute walk away the rebels have turned what....

Answer 1

It means that not far away (five-minute walk away), they changed (turned into) what should be his office into the headquarters of their self-declared state.

A five-minute walk away the rebels have turned what should be his office on the top floor of the region's barricaded administration building into the headquarters of their self-declared state.

Answer 2

The sentence is badly formed and punctuated. When a sentence starts with a phrase such as "A five-minute walk away," the phrase serves as a modifier further describing the word or word phrase immediately following the comma. In this case it seems to indicate that the rebels are a five-minute walk away. Doubtless the writer meant to say that it was Taruta's former office, now the headquarters of the rebels' self-declared state, that was a five-minute walk away.

The phrasal verb "turned into" is equivalent to the word "transformed."