Hi @emunem ,
Just verifying that it is a Nokia 3310 (2000) model and not the 3310 (2017/3G) model?
If so, then you can replace the [https://www.maxbhi.com/searchproducttype.html?model_id=6878|switch - supplier example only] (scroll down to find On/Off button - cost is ~$US4.00 + shipping).
You will need smd (surface mounted device) soldering skills and tools to do the repair.
I cannot find a switch actuator so you may have to contrive something to operate the switch once it is installed.
Just curious as to why you wish to fix this particular model phone because it is a 2G only phone and the 2G phone systems have been shutdown most everywhere and have been replaced by 3G, 4G and now 5G. So the phone will not work as a phone anymore even if you get it to turn on etc