Follow the instructions in the owner's manual. If you don't have one, go to a gunsmith.
You don't you throw it away, I once owned this gun as a youngster, I was shoot at by gang bangers when I reached for this POS it jammed, I sold it and went with a 44mag bulldog
25
First, it's not 25 mm, it's 25 ACP. Second, not very much. According to the Blue Book of Gun Values, the most it can be worth is about $50.00
25-50 USD
If you don't have an owner's manual, find a gunsmith.
25-65 USD
Follow instructions in owner's manual
25-50 USD
gun shops, gun shows, want ads, e-gunparts.com
$25-$50. Sorry- very low quality firearms.
50 USD
Effective range is 25-50m