there's been a few ways shown here on RRB over the years. Have you searched YouTube for a DIY hack?
I've only done it twice. Once I used the v of tree to hold it, and a long pipe for leverage. The other time I used boards for protection and drove over it with my car. I'm sure there are better ways.
You could use a board to protect the tube Strong rope should suffice . It's not ' brute ' force , but rather ' linear force a little at a time, and it springs back when it's ready
Press it, couple blocks of wood to the right thickness, so not to over bend. Place on floor, under garage door header, another block of wood, then a jack, long 2 x 4 above jack to header. Or hydraulic press..............Curt
An easy method is to reverse the fork and sit on the bike, and bump the front wheel against a wall. A little more complicated is the tourniquet method mentioned above, an axle in the fork, but use a ratchet strap around the post to tug it into shape