You have to grind off the weld first, then push it out, then reweld.
Go easy though pushing it out not to mushroom the end..harder to push thru.
Bing LiGHTBULB moment !!!!
Grind weld off.
Make a spacer stack to fit up to where your bearing cover fits, upper end, so bearing collar engages 75 % thread..
Now use the nut if you can figure out a good way to turn it.
Turn the nut, it will act like a jackscrew or puller, and suck that stem right out.
Do same both stems.
Final Step.. Buy 754 beer instead of paying shop to remove stems.
Then when you press back in to correct depth, reweld. I would weld prep both parts to get weld to stay flatter