FiveNights L. I’m assuming you mean that the head is stripped, and not actually broken clean off.
First advice is to use something like [product|IF145-118|these] as they’re a very handy kit to have for repairs.
Another option is to use some high temp solder, but this is a little more involved and can be tricky at first. Practice and patience is key. Soldering another precision screw driver (that you don’t use) to the head will often solve such issues I’ve found. I use high temp solder because it is a little more resistant to breaking than your low melt (pliable) solder.