Depending upon who mde it,
You can get a kit of internals from Cabela's which has a lot of parts for about 30 bucks.
VTI and Dixie Gun Works have parts and will talk to you on the phone with advice.
I'd buy the whole hand and don't try to replace the spring. Many on the forum disagree on the strength of the argument that a new hand can require fitting which can be finnicky. This is a good argument.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson