I'm a great one for having a go. You could say an item is screwed anyway, so you can't bugger it up any more. Vacuum cleaners*, circular saws, spectrophotometers, defibrillators etc, the usual straightforward stuff found in any modern home. It is always worth having a play. In the end, you learn something, and if you can't fix it, then call in the professionals.
Back to your wheel. In theory altering the nipples on the spokes positions the rim where you want it. The problem is that in many cases the nipples are very firmly rusted to the spokes, and the only sensible way is a rebuild....spokes cut out and new spokes and nipples substituted. Then we come into the "not much more for a complete new rim plus spokes territory"
So look on YouTube for the basics, try moving the nipples, then spend. Have a go yourself as a start, but it will all depend on the state and condition of the spokes and nipples.
Swarfy.
* Just battled changing a burnt out motor on a Dyson DC27 Vacco. If you meet Mr Dyson, shake him by the hand for a design that would defeat most casual repairers, if you get my drift.