OK, you'll need a lathe, tooling to accurately measure inside/outside dimensions, experience and skill to operate them, barrel vise, action wrench to start with. Headspace gauges, reamer, etc. It's not a quick thing to pickup and learn.
Finding a used barrel for a Tikka is rare at this time. Easier to buy a new barrel, thread, chamber and fit to your action.
You could silver solder the sights into the slots, file it down or turn in your lathe to fill in the notch and blue it. Cold blue is great for touch up, but hot blue will make it look original.
It's not that you can't do it, it's a matter of your skill, time and money to get the equipment necessary to complete the task.