I have seen this (pressing out and in), you need a press and some mounting tool/device. From my point it is a job for a mechanic, who knows to handle such jobs very well.
An alternative is to use a Bomber crown which can swap the steerer.
I might have some, but don't know from here without looking into my boxes ...
What steerer in detail do you need?
Got a pair of Z2's that have served me well for many years, but due to a new headset, stem and frame combo, the steerer is now a smidge too short.
They are of the 2001/non bolt in variety...
Question is, I know that the steerers are supposed to be bonded in and not removable; but I have heard some stories about people managing to get them out and swap them. Is this possible, or does anyone have any experience?